FRANKLIN  INSTITUTE  LIBRARY 

PHILADELPHIA,  PA. 
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THE  ARTS 

OP 

TANNING,  CURRYING. 

AND 

LEATHER-DRESSING. 


THE  ARTS 

OF 

TANNING,  CURRYING, 

AND 

LEATHER-DEESSING; 

THEORETICALLY  AND  PRACTICALLY  CONSIDERED 
IN  ALL  THEIR  DETAILS. 

EDITED  FROM  THE  FRENCH  OF 

J.  DE  FONTENELLE  AND  F.  MALEPEYRE, 


WITH  NUMEROUS  EMENDATIONS  AND  ADDITIONS, 
BY 

CAMPBELL  MORFIT, 

PRACTICAL  AND  ANALYTICAL  CHEMIST,  AUTHOR  OF  "APPLIED  CHEMISTRY," 
"CHEMICAL  AND  PHARMACEUTIC  MANIPULATIONS,"  ETC. 

>  »  o 

TLLUSTHATED  BY  TWO  HUNDRED  WOOD  ENaHAVINGS. 

>  ^       i  iO     ')     ,  ,      ,        ',         ,     ',    ,       J  ]  >  •   I  J   )    J  )"j 


PHILADELPHIA: 
HENRY    CAREY  BAIRD, 

No.  7  HART'S  BUILDING, 
SIXTH  STREET,  ABOVE  CHESTNUT. 

1852. 


TS 


Entered  according  to  Act  of  Congress,  in  the  year  1852,  by 

HENRY  CAREY  BAIRD, 

in  the  Clerk's  Office  of  the  District  Court  of  the  United  States  in  and  for  the 
Eastern  District  of  Pennsylvania. 


PHILADELPHIA  : 
T.  K,  AND  P,  G.  COLLINS,  PEINTERS. 


PREFACE. 


The  present  work  has  been  prepared  to  meet"  the 
growmg  demand  for  information  as  to  the  practical  ap- 
plication of  scientific  principles,  which  characterizes  the 
progress  of  the  arts;  and  is  offered  to  that  portion  of 
the  public  which  is  interested  in  the  branch  of  manufac- 
tures of  which  it  treats. 

The  first  intention  of  the  Editor  was  to  reproduce, 
in  translation,  the  French  Manual  of  J.  de  Fontenelle 
and  F.  Malepeyre,  but  in  the  course  of  his  labors  its 
imperfections  became  so  manifest  that  the  original  plan 
was  abandoned  for  a  substitute  which  would  better 
realize  his  purpose  of  making  a  full  and  comprehensive 
treatise  upon  the  manufacture  of  the  different  kinds  of 
leather.  To  this  end,  such  portions  of  the  French  work 
as  were  valuable  and  novel,  were  either  translated  or 
remodelled;  while  the  information  in  which  it  was  de- 
ficient, was  directly  supplied  or  derived  from  other 
sources. 

For  the  purpose  of  procuring  the  desired  information, 
inquiries  have  been  directed  over  a  wide  range  of  the 
country,  sometimes  by  letter,  and  frequently  in  person. 


vi 


PREFACE. 


In  this  way,  most  accurate  knowledge  has  been  obtained ; 
and  although,  often,  much  of  the  time  of  manufacturers 
and  others  has  been  exacted  in  giving  explanations  and 
descriptions,  these  have  always  been  rendered  with 
willingness,  and  with  the  manifest  desire  to  co-operate 
for  the  advancement  of  the  Art.  The  editor  takes 
pleasure  in  acknowledging  his  indebtedness  to  those 
who  have  so  kindly  assisted  him  by  contributing  im- 
portant facts,  and  desires  to  express  his  particular  obli- 
gations to  the  Hon.  Z.  Pratt,  Plon.  J.  C.  G.  Kennedy, 
Prof.  J.  C.  Booth,  Prof.  L.  D.  Gale,  and  S.  Sparhawk, 
Esq. 


CONTENTS 


PAGE 

Preface    v 

CHAPTER  1. 

INTRODUCTION  17 

CHAPTER  IT. 

THE  DIGNITY  OP  LABOR  WHEN  ASSOCIATED  WITH  INTELLIGENCE ,  WITH 
A  REFERENCE  TO  THE  CAREER  OF  ZADOCK  PRATT,  THE  TANNER.  25 

CHAPTER  III. 

OP  TAN  AND  TANNIN. 

Preparation. — Processes:  1.  Proust's.  2.  Deyeux's.  3.  Dize's. 
4.  Merat-Guillot's.  5.  Bouillon-Lagrange's.  6.  TromsdorfiF's. 
7.  Serturner's.  8.  Laubert's.  9.  Pelouze's.  10.  Domine's. 
11.  Mohr's. — Impure  tannin.  Chemical  properties  and  varie- 
ties: 1.  Tannin  from  catechu.  2.  Tannin  from  sumach,  kino, 
&c.  3.  Artificial  tannin.  4.  Tannin  from  various  sources. — 
Pure  tannin.    Chemical  properties  39 

CHAPTER  lY. 

GALLIC  ACID. 

Preparation. — Processes:  1.  Scheele's.  2.  Fiedler's.  3.  lire's. 
4.  Braconnot's.  5.  Kent's.  6.  Wetherill's.  —  Properties. — 
ElLAGIC  ACID  58 


'  viii 


CONTEXTS. 


CHAPTER  V. 

PAGE 

EXTRACTIVE.  ....  64 

CHAPTER  VI. 

TANNING  MATERIALS. 

Tanning  juices. —  Catechu,  japonica,  or  cutch:  1.  Cake  catechu. 
2.  Pegu  catechu.  3.  Bengal  catechu.  4.  Bombay  catechu.  5. 
Gambir.  6.  Arecha  catechu. — Kino. —  Vegetable  fungi:  Nut- 
galls;  Chinese  galls;  Aleppo  galls. —  Tree  leaves. —  Tea:  green; 
black. — Flowers  and  jiower  toi^s. — Fruits. — Seeds  and  hulls :  divi- 
divi;  squills;  valonia. —  Woods. — Roots:  leadwort;  filix  mas; 
rhatany;  leopard's  bane;  statice.  —  Barhs:  cinnamon;  birch; 
chestnut;  horse-chestnut;  sassafras;  larch;  hemlock;  hazel; 
beech ;  Lombardy  poplar ;  black  thorn ;  pomegranate ;  ash ;  elm  ; 
cinchona;  cork-tree;  poison  oak;  sumach;  willow;  sycamore; 
tamarisk;  winter's;  tulip-tree;  St.  Lucia;  wattle   ...  66 


CHAPTER  VII. 

OAK-BARKS. 

European  oaks  :  quercus  robur;  quercus  pedunculata;  quercus  ses- 
siliflora;  quercus  coccifera,  or  garronille.  —  American  oaks: 
quercus  falcata ;  quercus  rubra ;  quercus  prinus  montieola ;  quer- 
cus tinctoria;  quercus  alba;  quercus  coccinea;  quercus  ambigua ; 
quercus  virens      .........  95 

CHAPTER  VIII. 

BARKING  OF  TREES.  .         .  .104 


CHAPTER  IX. 

METHODS  OF  ESTIMATING  THE  TANNING  POWER  OF  ASTRINGENT 
SUBSTANCES. 

Processes:  Davy's;  Bell  Stephens's;  Warington's.    Table  of  the 
average  quantity  of  tannin  in  different  substances    .       .  .107 


CONTENTS. 


ix 


CHAPTER  X. 

TAN,  OR  POWDERED  OAK-BARK. 

PAGE 

Grinding  apparatus:  French  bark-mill;  BagnalFs  bark-chopper; 
Weldon's  bark-mill ;  Farcot's  bark-chopper;  Bourgeois's  bark-mill ; 
Lespinasse's  bark-mill ;  Wiltse's  bark-mill  and  breaker;  Birely's 
mill  113 

CHAPTEE  XL 

THE  STRUCTURE  AND  COMPOSITION  OF  SKIN. 

Corium ;  rete  mucosum ;  cuticle. —  Composition :  fibrine ;  gelatine ; 
albumen     .       .       .       .  •  137 

CHAPTER  XII. 

OF  THE  DIFFERENT  KINDS  OF  SKINS  SUITABLE  FOR  TANNING.  146 

CHAPTER  Xni. 

PRELIMINARY  TREATMENT  OF  SKINS. 

■JVa  SUING  AND  SOAKING. —  Of  the  influence  of  the  soahing-waterupon 
the  qualify  of  leather:  1.  Rain-water.  2.  Snow-water.  3. 
Spring  and  fountain  water.  4.  River-water.  5.  Lake-water.  6. 
Marsh-water.  7.  Well-water. — Swelling,  or  raising  :  raising 
by  lime;  raising  by  acids;  depilation  by  steam;  depilation  by 
caustic  soda;  depilation  by  sulphurets  of  calcium  and  sodium; 
cool  sweating ;  raising  and  depilating  by  barley ;  raising  by  sour 
tan-liquor ;  raising  by  yeast. — Working  ON  the  beam  .       .  154 


CHAPTER  XIY. 

TANNING  PROCESS. 

Tan  vats:  Brown's  vats;  Dessables's  process;  Herapath  and  Cox's 
process. —  Cropleather :  drying. — Beating  amd  rolling:  Debergue's 
machine;  Flotard  and  Delbut's  machine;  Berendorf's  machine; 
Cox's  rolling-mills;  Wiltse's  rolling-table       ....  204 


X  CONTENTS. 


CHAPTER  Xy. 

IMPROVED  PROCESSES. 

PAGE 

Seguin's  process;  oak  tanning;  Desmond's  process;  Getliffe's  pro- 
cess; Nossiter's  process;  Ogereau's  process     ....  243 

CHAPTER  XVI. 
vauquelin's  process.        .       .       .  254 

CHAPTER  XVII. 

ACCELERATING  PROCESSES. 

Berenger  and  Sterlingue's  process;  Squire's  process. —  Tanning  ly 
mechanical  pressure :  Spilsbury's  process;  Drake's  process;  Chap- 
lin's process;  Cox's  process;  J.  F.  Knowlis's  process;  Poole's 
process;  Hannoye's  process;  Danish  process ;  Rotch's  process;  S. 
Snyder's  process  .  •       .  263 

CHAPTER  XVIII. 

kkasley's  process  291 

CHAPTER  XIX. 
turnbull's  process, 
warington's  process   298 

CHAPTER  XX. 
hibbard's  patent  process.     .       .       .  307 

CHAPTER  XXI. 

leprieur's  process  310 


CHAPTER  XXII. 
tanning  with  extract  of  oak-bark  or  catechu. 
Burbridge's  process  


318 


CONTENTS.  xi 


PAGE 


CHAPTER  XXIIL 

HEMLOCK  TANNING. 

Pratt's  process ;  hydrometers ;  fulUng-mills        .       .       .  .320 
CHAPTER  XXIY. 

TANNING  WITH  MYRTLE  PLANT. 

Rap^nius's  process;  tanning  with  grape-skins;  tanning  with 

STATICE,  OR  MARSH  ROSEMARY;    ToIJRNELL's  PROCESS;  GaY- 

raud's  process;  mode  of  preparing  skins  by  means  of  tar 

AND  soot;  tanning  WITH  FURZE  338 

CHAPTER  XXY. 

ENGLISH  harness  LEATHER. 
BUTTS,  CALLED  "RED  LEATHER^  345 

CHAPTER  XXVI. 

CALF-SKINS. 

Kampffmeyer's  processes;  tanniDg  with  oak-bark;  tanning  with  divi- 
divi;  tanning  with  catechu ;  tanning  with  alder-bark;  "alumed" 
calfskins  349 


CHAPTER  XXYII. 

GOAT  AND  SHEEP  SKINS. 

True  morocco;  imitation  morocco;  skiver;  roan         .       .       .  361 
CHAPTER  XXVIII. 

HORSE-HIDES.  .         .         .  .366 


CHAPTER  XXIX. 
buck,  wolf,  and  dog  skins. 
Human  skins  368 


xii 


CONTENTS. 


.CHAPTER  XXX. 

PAGE 

BUFFALO;  OR     GRECIAN"  LEATHER.  .         .  309 

CHAPTER  XXXI. 

RUSSIA  LEATHER.       .         .         .  .372 

CHAPTER  XXXII. 

RED  SKINS.  .  .  .382 

CHAPTER  XXXm. 

WALLACHIA  LEATHER. 

Barley-dressings;  bran-dressings;  rye-dressings         .       .       .  385 
CHAPTER  XXXIV. 

MINERAL  TANNING. 

Bordier's  process;  Cavalin's  processes;  Dutch  or  mineral  tanning. — 
Dye-tanning :  Newton's  process     ......  395 

CHAPTER  XXXV. 

THE  TEXTURE  AND  QUALITY  OF  LEATHER,  AND  THE  MEANS  OF 

DISCOVERING  ITS  DEFECTS.         .  .         .  404 

CHAPTER  XXXVI. 

TAWING. 

Alumed  leather;  kid  leather;  imitation  kid;  housings  and  mats  409 
CHAPTER  XXXVII. 

HUNGARY  LEATHER. 

Kresse's  process;  Curandeau's  process       .       .       .       .  .415 


CONTENTS. 


xiii 


CHAPTER  XXXYIII. 

OILED  LEATHER. 

TAGE 

Chamois  leather;  wash  leather;  losh  leather;  Nisbet's  process     .  433 


CHAPTER  XXXIX. 

TANNING  AS  PRACTISED  BY  THE  MONGOL  TARTARS. 


Tanning  as  practised  by  the  Indians  440 

CHAPTER  XL. 

SHAGREEN.  ....  443 

CHAPTER  XLI. 

PARCHMENT. 

Vellum   446 

CHAPTER  XLII. 
leather  bottles. 
Leather  tubes  450 

CHAPTER  XLin. 

TANNING  OF  CORDAGE  AND  SAIL-CLOTH.       .  .  452 


CHAPTER  XLTV. 
glazed,  or   patent'^  leather. 
Didier's  process;  Nossiter's  process  453 

CHAPTER  XLV. 

HALVORSON's  PROCESS  FOR  RENDERING  HIDES  HARD  AND 

TRANSPARENT  458 


XIV  CONTEXTS. 


CHAPTER  XLVI. 

CURRYING. 

PAGE 

Dipping;  sLaving;  pommelling;  stretching;  working  with  the  round- 
knife. — Stretched  leather;  sleeked  leather;  grained  leather;  water 
leather;  oiled  leather;  wax  leather;  English  leather;  white  leather; 
common  russet  461 

CHAPTER  XL VII. 

CURRYING  OF  CALF-SKINS. 

Oiled  calf-skins;  tallowed  skins;  English  skins;  wax  skins;"  grained 
skins;  calf  belt-leather        .......  489 

CHAPTER  XLYIII. 

CURRYING  OF  GOAT-SKINS. 

Morocco;  Boolcliout  and  Coclien^ s  rolling-mill     .       .       .  .497 
CHAPTER  XLIX. 

RED  LEATHER  502 

CHAPTER  L. 

FAIR  LEATHER. 
 505 

CHAPTER  LI. 

WATER-PROOF  DRESSINGS. 

Smith  and  Thomas's  process;  Nenorj's  process;  Deane's  process; 
H.  C.  Jennings's  process  507 


Booth's  process 


CHAPTER  LII. 

Perkins's  machine  for  pommelling  and  graining  leather.  514 


CONTENTS. 


XV 


CHAPTER  LIII. 

SPLITTING,  SHAVING,  FLESHING,  AND  CLEANSING  MACHINES. 

PAGE 

Degrand's  machine;  Giraudon's  machine;  Richardson's  machine; 
Seguin's  machine;  Nossiter's  machine  518 

CHAPTER  Liy. 

EMBOSSING  OF  LEATHER. 

Bernheim  and  Labouriau's  process;  F.  W.  East's  process    .       .  530 


CHAPTER  LY. 

GUT-DRESSING. 

Preparation  of  the  intestines  of  cattle;  disinfection  of  the  workshop, 
and  mode  of  suppressing  putrefaction;  goldbeater's-skin;  lathe- 
cords;  catgut;  whip-cords;  hatters'  cords;  clock-makers'  cords; 
musical-instrument  strings    .       .       .       .       .       .  .530 


ERRATA. 


Page  34,  9tli  line  from  top,       for  "wall,"       read  well. 
"    35,  7tli  line  from  bottom,       "empires,"  .  "  emprises. 
"  162,  llth  "  "  "peck,"        "  quart. 


THE 


ARTS  OF  TANNING,  CURRYING, 

AND 

LEATHER-DRESSING. 


CHAPTEE  I. 

INTRODUCTION. 

The  art  of  tanning  is  that  by  which  animal  skins  are 
converted  into  leather,  a  product  possessing  certain  cha- 
racteristic properties,  differing  entirely  from  those  of  the 
raw  material,  and  eminently  adapting  it  to  the  useful 
purposes  for  which  it  is  employed.  These  properties  are 
of  a  physical  nature,  and  vary  with  the  kind  of  skin 
employed,  and  the  modifications  of  the  process  which  it 
undergoes.  Chemically  considered,  however,  leather 
proper,  whatever  its  kind,  is  a  definite  compound  of  tan- 
nin and  gelatine,  possessing  the  all-desirable  requisites  of 
durability,  pliability,  inalterability,  insolubility  in  water, 
and  great  power  of  resisting  the  action  of  chemical  re- 
agents. When  mineral  or  earthy  substances  are  used  as 
the  leather-making  agents,  the  result  is  a  compound  of 
gelatine  with  the  base  employed,  and  is  more  or  less  in- 
destructible, according  to  the  nature  of  the  material  and 
the  circumstances  under  which  the  combination  takes 
place. 

2 


18 


INTRODUCTION. 


Tanning,  as  an  empirical  art,  dates  back  to  antiquity; 
but  the  methods  resorted  to  in  early  times,  consisted  of 
little  more  than  merely  cleansing  and  drying  the  skins; 
and  thus  prepared,  the  latter  were  used  for  clothing,  &c. 
This  mode,  however,  was  very  imperfect,  for  the  bibulous 
nature  of  the  skins  caused  them,  upon  the  reabsorption 
of  moisture  by  exposure,  to  resume  their  original  liability 
to  putrefaction  and  injury.  In  later  times,  these  defects 
were  remedied  by  immersing  the  cleansed  and  de-haired 
skins  in  infusion  of  oak-bark,  or  solution  of  alum;  and 
thus,  by  effecting  a  union  between  one  or  more  constituents 
of  the  liquor  and  the  gelatinous  tissue  of  the  skin,  pro- 
ducing a  new  compound  endowed  with  desirable  proper- 
ties not  possessed  by  its  original  components.  The  prin- 
ciples governing  this  reaction,  have  been  in  more  recent 
days,  developed  by  the  investigations  of  Lewis,  Proust, 
Seguin,  Deyeux,  McBride,  and  Sir  H.  Davy;  and  it  is 
owing  to  the  researches  of  these  inquirers,  that  the 
occupation  of  the  tanner  has  been  elevated  from  the 
condition  of  an  empirical  pursuit,  to  that  of  an  art  based 
upon  recognized  scientific  principles. 

Unfortunately,  however,  the  efforts  of  theoretic  in- 
vestigators have  not  always  been  reciprocated  by  practi- 
cal men ;  and,  though  many  improvements  in  the  mani- 
pulations of  the  art  have  been  made  by  the  aid  of  in- 
geniously contrived  machinery,  and  much  has  been  done 
to  hasten  the  process,  by  promoting  the  absorption  of  the 
tanning  principle  by  mechanical  and  philosophical  means, 
any  economy  of  time  that  may  have  been  thus  accomplish-  • 
ed,  is  counterbalanced,  in  the  present  state  of  the  art,  by 
a  corresponding  depreciation  of  the  quality  of  the  leather. 
We  base  a  hope  for  a  more  propitious  future  in  this  re- 
spect, upon  the  growing  interest  in  applied  science  which 
characterizes  the  times,  and  already,  Prof  Gale,  of  the 


INTRODUCTION. 


19 


Patent  Office,  has  commenced  an  examination  of  the 
tannin-yielding  trees  of  the  United  States,  beginning 
with  the  oaks.  This  course  is  with  a  view  of  comparing 
the  products  of  the  same  trees  growing  in  different  lati- 
tudes, so  as  to  show  the  effect  of  climate  in  modifying 
the  secretion  of  tannin  by  the  organism  of  the  growing 
plant — a  work  which  will  prove  as  serviceable  to  the 
tanning  interest,  as  it  is  creditable  to  the  disinterested- 
ness and  professional  skill  of  its  author. 

Leather  was  largely  in  use  among  the  ancient  Egypt- 
ians, and  the  workers  of  that  material  were  so  numerous 
that  the  Memnonian  quarter  of  Thebes  was  characterized 
as  their  especial  locality.  Their  skill  in  fashioning  it 
was  so  great,  that  ornaments  of  all  shapes  and  devices 
were  made  from  it.  As  far  back  as  900  years  before 
Christ,  leather  was  made  by  them  into  tapestry;  and 
many  of  the  Egyptian  tombs  bear  representations  of 
artificers  in  leather  engaged  in  the  several  branches  of 
their  vocation. 

The  principal  steps  in  the  manufacture  of  leather  are 

1.  The  Washing  and  Soaldng^  for  the  purpose  of  cleans- 
ing and  softening  the  skins,  and  preparing  them  for — 

2.  The  Depilation  or  Removal  of  the  Hair. — This  is 
effected  by  the  use  of  lime  or  other  substances  which 
destroy,  dissolve,  or  soften  the  bulbous  roots  of  the  hairs, 
and  thus  facilitate  their  removal  by  mere  mechanical 
scraping  with  a  blunt-edged  knife.  During  this  part  of 
the  process,  another  important  end  is  generally  accom- 
plished, in  the  swelling  of  the  tissues,  and  their  prepara- 
tion for  the  more  complete  and  easy  absorption  of  the 
tanning  principle.  The  primitive  mode  of  removing  the 
hair,  was  that  of  shaving  it  off  with  a  knife,  but  the  use 
of  hrae  was  known  even  among  the  early  Egyptians. 


20  INTRODUCTION. 

When  the  rationale  of  the  depilation  is  better  understood 
hy  practical  tanners,  the  slow  and  inconvenient  process 
of  depilation  by  means  of  lime,  will  probably  give  place 
to  more  effective,  rapid,  and  economical  methods,  such 
as  the  use  of  the  hydrosulphuret  of  calcium. 

3.  Tanning. — This  step  consists  in  promoting  the  com- 
bination of  the  gelatinous  tissue  with  tannin,  by  immers- 
ing the  softened  and  unhaired  skins  in  an  infusion  of  oak- 
bark,  or  other  substances  containing  tannin.  The  tan- 
ning influence  is  probably  not  exerted  solely  by  the  tan- 
nin, but  also  partly  by  the  extractive  matter,  more  or 
less  of  which  always  exists  in  tanning  material.  During 
the  soaking,  the  epidermis  of  the  skin  disappears,  and  the 
tissue  of  the  latter  is  gelatinized,  and  thus  predisposed 
to  chemical  union  with  the  tannin.  This  gelatinization 
of  the  tissue  is  all-essential,  and  is  promoted  doubtless 
by  the  gallic  acid  fermentation  of  the  tanning  material. 
This  is  the  more  probable,  since  the  same  effect  may  be 
produced  by  the  use  of  very  dilute  acetic  and  sulphu- 
ric acids,  and  since  gallic  acid  has  no  primary  or  direct 
influence  on  the  tanning.  Time,  exposure  to  moisture, 
to  air,  and  a  temperature  of  77°  to  86°,  F.,are  the  requi- 
sites for  this  fermentation,  which  is  developed  by  the 
action  upon  tannin  of  a  ferment  which  is  always  present 
in  tanning  material,  converting  it  into  gallic  acid.  In 
consequence  of  this  change,  the  prolonged  exposure  of 
the  liquor  diminishes  its  tanning  power. 

4.  Drying,  rolling,  and  other  operations  intended  to 
perfect  the  quality  and  appearance  of  the  leather. 

Leather  is  employed  for  many  useful  and  ornamental 
purposes,  and  numerous  are  its  applications  to  various 
branches  of  industry.  Besides  its  extensive  use  for 
coverings  for  the  head  and  foot,  wearing  apparel,  sad- 


1 


INTRODUCTION. 


21 


clleS;  harness,  carriages,  and  the  purposes  of  the  book- 
binder, it  is  Largely  employed  for  the  embellishment  of 
objects  of  taste  and  ornament. 

Independently  of  the  direct  importance  of  the  leather 
trade,  it  exerts  a  very  decided  incidental  influence  in  de- 
veloping the  resources  of  a  country,  by  giving  value  to 
certain  materials  used  in,  and  resulting  from  the  manu- 
facture. Besides  the  immense  quantit}^  of  bark  which 
it  consumes,  it  furnishes  the  raw  material  which  gives 
employment  to  thousands  of  artisans,  and  it  has  built  up 
colonies  and  towns  which  owe  their  origin  and  progress 
entirely  to  the  interests  connected  with  it.  Even  the 
waste  materials  of  slaughter-houses,  tanneries,  curriers'- 
shops,  and  workers  in  leather,  have  important  applica- 
tions; the  horns  serving  for  the  manufacture  of  combs, 
buttons,  and  umbrella  furniture,  the  hair  for  plasterers' 
use,  the  spent  lime  for  the  farmer,  the  skin-clippings  for 
the  glue-boiler,  and  the  leather-shavings  for  the  manufac- 
turer of  the  prussiate  of  potash. 

The  following  statements  will  suffice  to  give  an  idea 
of  the  vast  extent  and  rapid  increase  of  the  trade  in 
leather. 

In  France,  a  country  eminent  for  the  quantity  and 
quality  of  the  leather  which  it  produces,  the  average 
number  of  skins  annually  converted  into  leather  is 

Of  Oxen  and  Cows     .       .       .  857,000 

"  Calves   2,032,000 

"  Horses  .       .       .       .       .  111,000 

amounting  to  3,000,000  of  whole  skins,  exclusive  of 
sheep  and  calf  skins ;  and  equal  in  money  value  there, 
to  the  very  large  sum  of  $7,171,630. 

In  the  United  States,  the  manufacture  of  leather,  only 


22 


INTRODUCTION. 


beginning  to  be  of  much  importance,  in  the  early  part 
of  the  present  century,  has  been  rapidly  extended,  until 
it  has  become — with  its  allied  and  dependent  arts — one 
of  the  most  prominent  elements  of  national  prosperity. 
Conducted  originally  in  the  most  simple  and  primitive 
manner,  the  expenditure  both  of  time  and  labor  is  now 
materially  reduced  by  new^  processes  and  modes  of  treat- 
ment, which  ow^e  their  beginning  to  various  improve- 
ments which  commenced  in  the  year  1803  in  Massachu- 
setts. These  improvements  were  the  substitution  of 
water-power  for  manual  labor  in  many  of  the  most  labo- 
rious parts  of  the  manufacture,  such  as  the  softening  and 
cleansing  of  the  hides  before  tanning,  the  grinding  of 
the  bark,  the  pumping  of  the  tan-liquor  from  one  vat  to 
another,  and  the  rolling  and  smoothing  of  the  leather. 
After  these  advancements  in  the  progress  of  the  art,  fol- 
io w^ed  the  diminution  of  the  quantity  of  lime  used  for 
depilation,  the  application  of  heat  to  bark  in  leaches, 
the  more  frequent  use  of  decoction  of  bark  as  the  tan- 
ning agent,  the  introduction  of  steam-power,  and  the 
employment  of  various  machines  for  splitting,  shaving, 
graining,  and  finishing  leather.  In  1829,  36,360  sides 
of  sole  leather  were  tanned  in  one  establishment,  in  the 
town  of  Hunter,  Greene  County,  New  York.  They 
weighed  637,413  pounds,  and  were  manufactured  with 
the  labor  of  forty-nine  hands,  and  with  3200  cords  of 
bark.  A  reference  to  Chapter  XXIIL,  containing  an 
account  of  the  Prattsville  tannery,  will  give  to  the 
reader  an  idea  of  the  expenditure  of  labor  and  capital, 
and  the  results  obtained  hj  them,  in  a  modern  Ameri- 
can tanning  establishment. 

In  New  York,  wliich  is  the  great  commercial  mart  for 
leather  from  every  source  of  manufacture,  the  number 


INTRODUCTION. 


23 


of  sides  of  sole  leather  inspected  during  the  last  five 
years,  was  as  follows : — 


1847  ....  1,168,332 

1848  ....  1,325,126 

1849  ....  1,750,231 

1850  .       .     ^.       .  2,098,740 

1851  ....  2,185,553 


For  the  same  years,  the  value  of  raw  hides  and  skins, 
and  of  manufactured  leather  imported  into  the  United 
States,  was,  in 

Eaw  Hides  Manufactures 
and  Skins.         of  Leather. 

1847  (ending  31st  June)     $1,529,948  $135,217 


1848  "  "  "  4,262,069  208,993 

1849  "  3,507,300  210,143 

1850  "  "  "  4,799,031  362,409 

1851  "  "  "  5,964,838  411,795 


We  append  a  statistical  table,  compiled  from  the  re- 
turns of  the  seventh  census,  and  showing  the  present 
condition  of  the  tanning  interest  in  the  United  States : — 


24 


INTRODUCTION. 


Hanbs 

BIONTHLT 

^^3/1 UG  of 

Employed. 

Wages. 

Yalue 

Capital 

States. 

Kaw 

6 

^1 

InTestcd. 

Material. 

a 

a 

o 

'3 

1 

of  Product. 

Maine 

213 

732,747 

892,343 

787 

q 

1  7  09Q 

9Q 

1,620,636 

163 

441,975 

543,779 

1  1  7*^7 

900,421 

V  Cl  lllUll  V 

152 

346,250 

357,946 

^Q7 

8  807 

587,466 

i\Tn  <5<*i  plm  «!ptt«! 

XTXcl.oOctj\^ll  Hoc  U  L  O 

246 

1,377'725 

2,311,178 

1 , 0  i  u 

zll  94f; 

qAQ 

3,519,123 

Rhode  Island 

10 

42,900 

40,615 

oo 

89Q 

75,040 

n  f>n  11  pp  ti  r>n  t. 

115 

360,500 

453,854 

407 

1  A  097 

731,000 

New  York 

942 

5,025,143 

6,065,221 

Q1  d 

Oi 

103,171 

^yo 

9,804,000 

N^pw  .TpTCiPv 

133 

572,857 

423,537 

ft  Q/f  A 

724,466 

T^PTin  sivl  vn  in  fi. 

i  dlllo  y  A  >  €XXL1.<JU 

1  039 

3,540,318 

3,169,309 

O  Q7ft 

o 
A 

04,  /o4 

17 

5,275,492 

Delaware 

16 

99,350 

99,620 

1  no 
lUo 

Z,Ood 

163,742 

A  To       n  Ti  fl 

116 

628,900 

725,612 

A  70 

Q  AO  /( 

c5,Uo4 

1,103,139 

341 

676,983 

498,926 

yuu 

a 
D 

1  q  A/I  Q 

894,877 

151 

251,055 

191,237 

Q79 

1 

0,291 

A 

4 

352,535 

South  Carolina 

91 

184,335 

131,679 

0  fiC? 
0,0D/ 

261,332 

(tPatd"!  n. 

140 

262,855 

185,604 

7  1  07 

261,586 

Florida 

4 

9,400 

4,300 

1  0 

1  on 

9,200 

xVlabama 

149 

200,570 

158,247 

40/ 

0 

7  7on 

A  Q9  4 

40 

385,911 

^lississippi 

■  92 

145,615 

111,474 

OA  A 

Q 

9?^ 

Jo 

229,407 

Louisiana 

15 

88,800 

26,440 

01 

q 
o 

you 

99 

55,025 

Texas 

22 

83,850 

18,624 

AQ 

1 

1  007 

1  0 

52,050 

Arkansas 

51 

42,100 

35,230 

J.  iU 

i,oI4 

78,774 

Tennessee 

394 

490,320 

896,159 

915 

6 

14,338 

32 

746,484 

Kentucky 

275 

763,455 

537,147 

877 

2 

14,417 

9 

985,267 

Ohio 

706 

1,840,389 

1,118,080 

1,826 

85,830 

1,964,591 

Michigan 

60 

OOr*  AAA 

2ob,000 

265 

6  782 

ot'O  no  A 
000,980 

Indiana 

358 

514,897 

405,838 

836 

"2 

I5I199 

i'i 

714,818 

Illinois 

96 

188,373 

129,907 

240 

5,145 

244,028 

Missouri 

148 

228,095 

247,956 

412 

"5 

8,306 

41 

466,241 

Iowa 

14 

20,350 

10,745 

28 

543 

24,520 

Wisconsin 

8 

78,950 

93,380 

75 

1,710 

175,710 

New  Mexico 

1 

500 

200 

3 

60 

940 

Dist.  of  Columbia 

2 

25,000 

25,600 

10 

270 

40,000 

Total. 

6,263 

18,900,557 

19,613,237 

20,909 

102 

416,214 

970 

32,861,796 

About  6,000,000  skins  of  sheep,  goats,  and  other  small 
animals,  are  tanned  and  dressed  annually,  which  are  not 
included  in  the  above  table. 


CHAPTER  II. 


THE  DIGNITY  OF  LABOH  WHEN  ASSOCIATED  WITH  IN- 
TELLIGENCE; WITH  A  REFERENCE  TO  THE  CAREER 
OF  ZADOCK  PRATT,  THE  TANNER. 

No  one  of  the  numerous  phases  of  modem  extrava- 
gance is  more  fraught  with  danger  to  the  institutions  of 
society,  and  the  general  welfare  of  its  members,  than 
the  increasing  and  indefinite  desire  for  changes  in  the 
established  relations  of  intelligence,  labor,  and  capital, 
and  the  attempts  to  arrive  at  an  Utopian  state  of  exist- 
ence, in  which  all  men  shall  be  producers  and  consumers 
in  a  certain  fixed  ratio,  irrespective  of  their  original  or 
acquired  advantages  of  ability  and  fortune. 

The  production  of  the  greatest  good  to  the  greatest 
number,  should  certainly  be  an  axiom  of  public  policy, 
as  well  as  a  philanthropic  hope ;  but  it  is  not  to  be  ac- 
complished by  either  theorists  or  moralists.  It  must 
depend  for  its  fulfilment  upon  the  combination  of  the 
results  of  individual  toil  and  intelligence,  sanctified  by 
contentment  and  devotion  to  the  duties  of  our  being,  and 
preserved  by  a  recognition  of  those  fixed  laws  which 
have  made  men  unequal  both  in  mental  aptitude  and 
physical  circumstances. 

If  man  were  the  creator  of  a  system  for  his  own  pur- 
suits, he  would  find  it  necessary  to  constitute  diversities, 
so  that  the  inequalities  would  produce  emulation,  laud- 
3 


26 


THE  DIGNITY  OF  LABOR. 


able  ambition,  enterprise,  and  the  numberless  qualities 
which  make  up  the  sum  total  of  the  good  purposes  of 
life. 

If  all  men  were  made  alike  rich  or  alike  poor,  only  a 
momentary  state  of  circumstances  would  be  produced,  a 
starting-point,  from  which,  at  the  very  first  step,  each 
one  would  begin  to  diverge  according  to  his  capacity ; 
and  there  would  never  again  be  such  a  condition  as  that 
at  the  beginning. 

Those  who  attempt  to  bring  society  together  by  arti- 
ficial means,  such  as  socialism,  and  expect  to  hold  it  in 
compact  by  the  influences  of  mere  dogmas  or  doctrines 
of  creed,  are  visionary  reasoners,  who,  in  contemplating 
the  desired  change  in  the  mirrors  of  their  own  fancies, 
would  starve  by  their  ideal  creations,  if  it  were  not  for 
the  industry  of  those  who  deal  in  tried  realities. 

There  are  two  great  levers  which  sustain  us :  the  one 
is  employment;  the  other,  the  knowledge  of  how  to  re- 
gulate and  improve  it.  In  other  words,  they  are  the 
union  of  occupation  and  instruction.  Nothing  can 
give  more  satisfaction  to  the  mind  than  the  enjoyment 
of  the  necessaries  and  comforts  of  life,  flowing  from  the 
industry  of  him  who  earns  them.  This  is  the  fruit  of 
occupation ;  and  the  improvements  of  society  follow  in 
proportion  as  the  occupied  mind  advances  in  proper  cul- 
tivation. 

The  vain  idea  that  labor  is  inconsistent  with  learning 
or  respectability  is  one  of  the  attributes  of  weak  minds, 
ignorant  of  the  nature  of  the  ligaments  which  bind 
society  together.  It  is  one  of  the  follies  of  antiquated 
fashion,  which  is  passing  away ;  and  we  are  now  begin- 
ning to  consider  the  mechanic  trades,  and  all  branches 
of  honest  industry,  as  the  co-ordinate  and  necessary  asso- 
ciates of  education,  integrity,  and  manliness. 


THE  DIGNITY  OF  LABOR. 


27 


It  may  not  be  inappropriate  to  the  foregoing  remarks, 
or  foreign  to  the  purpose  of  this  work,  to  refer,  in  this 
connection,  to  the  career  of  one,  a  large  part  of  whose 
life  has  been  spent  in  successful  devotion  to  the  pursuits 
of  which  we  are  about  to  treat;  a  career  which  has  illus- 
trated in  a  striking  manner  the  advantages  of  united 
industry  and  intelligence,  and  one  which  furnishes  the 
strongest  incentives  to  the  exercise  of  those  qualities  on 
the  part  of  others. 

Mr.  Pratt  is  a  native  of  Rensselaer  County,  New  York ; 
and  was,  at  an  early  age,  an  assistant  in  his  father's  tan- 
nery. When  a  boy,  he  had  the  opportunity  of  being 
present  at  the  funeral  of  the  great  Washington ;  an  event  ♦ 
which  was  calculated  to  consecrate  his  patriotism,  and 
operate  as  a  political  sacrament  of  devotedness  to  all 
that  might  benefit  his  country  and  his  race. 

Sometimes  the  career  of  life  is  directed  by  unconsidered 
impulses  and  accidental  events.  The  humble  herdsman 
hears  the  mysterious  voice  of  his  destiny  calling  to  him 
from  the  burning  bush,  to  become  the  future  lawgiver 
of  Israel.  The  shepherd  of  the  Alps,  in  pointing  out 
the  road  to  an  inquiring  churchman,  begins  his  own  path 
to  the  honors  of  the  papal  see.  And  so,  in  minor  call- 
ings of  life,  are  men  directed  by  seeming  casualties,  that, 
when  lightly  seen,  are  considered  as  mere  incidents  upon 
the  exterior  of  life,  having  no  connection  with  the  past 
or  the  future. 

The  history  of  the  social  operations  of  mankind, 
teaches  us  that,  in  all  periods  of  time,  apparently  trifling 
events  have  altered  the  destinies  of  individuals  as  well 
as  of  nations,  and  have  had  their  influence  upon  ages  to 
come. 

Sometimes  the  progress  of  oppression,  rising  through 
a  series  of  ages  to  its  climax,  exhausts  its  own  powers, 


28 


THE  DIGNITY  OF  LABOE. 


and,  in  the  form  of  revolution,  builds  up  a  system  of 
human  freedom  upon  the  ruins  of  tyrannic  power. 

Sometimes  intolerance  drives  a  few  of  the  faithful  of 
a  narrow  sect  from  the  homes  of  their  forefathers  to  the 
shores  of  a  new  and  unexplored  land,  which,  in  time, 
becomes  the  asylum  as  well  as  the  hope  of  the  oppressed 
in  every  form. 

The  wrongs  done  by  kings  to  their  subjects  are  the 
precursors  of  the  grants  of  rights  in  future  ages.  The 
flight  of  the  persecuted  is  the  first  fluttering  of  the 
wing  of  liberty  that  is  seen  to  come  in  after  times.  The 
little  bark  of  the  pilgrims  is  the  compressed  type  of  the 
mighty  argosies  that  shall  hereafter  spread  their  canvas 
to  the  commerce  of  the  world.  So,  too,  is  the  industry 
of  the  single  and  gifted  laborer,  who,  beginning  his  course 
under  the  auspices  of  good  example,  and  having  a  heart 
suited  to  a  proper  fellowship  with  man,  is  placed  in  a 
category  or  current  of  association  and  action,  which  brings 
out  a  development  of  the  faculties  with  which  Providence 
has  endowed  him.  The  first  steps  in  his  career  are  all 
connected  antecedents  of  his  future.  All  good  and  all 
evil  have  their  respective  relationship ;  and  there  is,  per- 
haps, metaphysically,  no  one  act  in  either  current  which 
could  be  said  to  stand  alone ;  each  has  its  precursor  and 
its  consequent. 

Every  man  seems  to  be  surrounded  by  his  appropriate 
atmosphere  of  life ;  and  all  its  particles  are  suited  to  the 
course  he  is  to  pursue.  The  early  steps  partake  of  the 
element  with  which  he  is  encompassed ;  and  so  he  goes 
on,  accomplishing  the  special  principle  which  belongs  to 
his  nature,  from  the  first  germ  of  action  to  the  last  efibrt 
of  intelligence. 

Whether  this  natural  fixedness  of  object  and  bent  of 
pursuit  entitle  an  individual  to  any  personal  credit  for 


THE  DIGNITY  OF  LABOR. 


29 


what  he  may  do  in  life,  it  is  not  necessary  to  determine. 
Sufficient  is  it  for  us  to  say,  in  recounting  the  actions  of 
men,  that  they  were  good ;  and  that  a  wise  Providence 
has  made  use  of  them  as  instruments  and  examples  for 
such  a  purpose. 

It  is  a  happy  reflection  to  believe  that  we  are  acting 
the  part  of  beneficial  agents  in  the  general  concerns  of 
life;  and  that,  if  we  are  even  only  like  animated  plants, 
we  are  of  those  whose  exhalations  are  healthy  and  yield 
grateful  odors. 

The  career  of  the  subject  of  this  memoir  is  an  illustra- 
tion of  the  influences  of  early  beginnings.  He  was,  while 
engaged  in  his  father's  tannery,  learning  the  habit  as  well 
as  value  of  industry.  His  presence  at  the  funeral  of  the 
father  of  his  country  was  an  act  of  patriotic  respect,  in- 
spired by  what  his  young  mind  had  learned  at  the  fire- 
side of  his  parents.  Here,  then,  were  two  principles, 
from  which  all  his  future  actions  might  have  drawn  their 
coloring.  As  the  beginnings  were  good,  so  were  the 
results ;  and  we  find  those  currents  of  excellences,  enter- 
prise  and  patriotism,  running  together  parallel  in  his  life. 
He  became  in  due  time  an  exemplary  mechanic,  and 
soon  established  himself  in  successful  business.  But 
when  the  country  required  the  services  of  her  sons  for 
war,  we  find  him,  impelled  by  the  impulse  of  patriotic 
duty,  serving  as  a  soldier  in  her  defence. 

After  a  series  of  enterprises  in  commerce  and  other 
occupations,  and  serving  the  general  government  in  her 
armies,  and  his  own  particular  State  in  her  enrolments,  in 
high  military  capacities,  we  see  him  returning  to  civil 
life  with  new  emprises  in  his  mind.  In  1825,  he  made 
the  beginning  of  what  is  now  the  flourishing  town  of 
Prattsville  in  New  York.  The  site  was  selected  on  ac- 
count of  its  advantages  for  water-power.    Then,  it  was 


30  THE  DIGNITY  OF  LABOK. 

a  rude-looking  place,  a  mere  sloping  hill  covered  with 
woods,  at  whose  base  were  a  few  small  tenements  with 
their  humble  inmates.  Since  that  time,  it  has,  through 
his  agency  and  its  accessories,  become  an  important  and 
populous  town,  the  sons  and  daughters  of  which,  if  they 
do  not,  as  those  of  the  happy  valley  of  Rasselas,  live 
only  to  know  the  soft  vicissitudes  of  pleasure  and  repose, 
at  least  enjoy  the  diversified  blessings  arising  from  fruit- 
ful occupation,  industry,  and  devotion. 

He  was,  some  years  after,  elected  to  Congress,  and 
also  chosen  a  democratic  elector  for  President  and  Vice- 
President  of  the  United  States. 

During  his  term  of  service  in  the  national  councils,  he 
certainly  manifested  great  zeal  and  most  laudable  inten- 
tions, applying  his  time  and  talents  to  the  accomplish- 
ment of  much  that  was  beneficial  to  the  country. 

It  is  here  that  we  may  pause  to  consider  how  much  is 
done  in  the  association  of  labor  with  intelligence.  The 
physical  industry  of  man  is  certainly  a  high  quality ;  but, 
vigorous  as  it  is,  it  gains  so  much  by  its  association  with 
a  cultivated  intellect,  that  while  the  one,  when  alone, 
resembles  the  rough  materials  of  handicraft,  and  the 
other  the  latent  genius  that  is  to  fashion  them,  they 
both  united  represent  the  perfection  of  skill  and  its  fruit- 
ful application  to  the  production  of  human  happiness. 

In  former  days,  trades  were  merely  physical ;  none  of 
the  sciences,  and  but  few  branches  of  the  fine  arts  entered 
into  their  action.  True,  there  were  some  few  exceptions 
dependent  upon  individual  condition  and  scholarship; 
but  generally,  labor,  in  any  calling,  was  strictly  and  ex- 
clusively mechanical.  There  is  now,  however,  a  pro- 
gressive spirit  which  belongs  to  the  times.  Whether  it 
has  resulted  from  the  institutions  of  this  country,  which, 
by  casting  off  the  trammels  of  political  tyranny,  and  by 


THE  DIGNITY  OF  LABOR. 


31 


the  abundance  of  our  land  for  an  easy  support,  have 
enabled  men  to  think  more  freely  and  consistently  with 
the  objects  of  their  creation  and  position,  or  is  a  part  of 
a  pervading  principle  which  the  Divine  Being  has  per- 
mitted to  spread  through  the  world,  is  a  problem  for  so- 
lution. Be  this  as  it  may;  we  see  that  there  is  evidently 
an  advance  in  the  different  trades  and  their  branches  ]  a 
more  intimate  relationship  between  mind  and  the  labors 
of  the  operator ;  a  clearer  working  through  the  lights  of 
reason;  so  that,  even  among  the  inferior  callings,  the 
lamp  of  science  sheds  its  rays,  even  if  it  is  only  seen  in 
flickerings  from  the  distance  at  which  it  stands. 

The  position  of  Mr.  Pratt,  as  a  member  of  Congress, 
no  doubt  gave  him  great  insight  into  subjects  germane  to 
his  genius,  as  well  as  to  those  of  national  polity,  in  which 
he  was  necessarily  an  actor. 

There  is,  perhaps,  no  pursuit  in  which  so  much  general 
knowledge  of  men,  of  the  interests  which  concern  them, 
the  structure  of  political  society,  and  the  various  subjects 
of  national  relations,  can  be  acquired,  as  in  that  of  legis- 
lation. 

There,  in  the  councils  of  the  nation,  every  representa- 
tive who  has  ears  and  eyes  of  understanding,  is  per  force 
of  position  obliged  to  learn ;  and  when  to  the  opportuni- 
ties as  well  as  necessity  of  learning  is  added  the  inclina- 
tion, and  still  further  the  ambition  for  knowing,  the  result 
is  great,  in  acquisition. 

There  is  scarcely  a  subject  of  any  general  concern  pre- 
sented for  the  consideration  of  Congress,  that  does  not 
involve  great  research;  embracing  in  various  ramifica- 
tions a  diversity  of  knowledge  with  which  members  must 
make  themselves  acquainted.  The  discussion  of  a  new 
tariff  brings  out  a  knowledge  of  our  national  wants,  our 
resources,  our  relative  interests  in  the  respective  States 


32 


THE  DIGNITY  OF  LABOR. 


and  with  other  countries,  the  character  and  extent  of 
our  manufactures,  the  special  articles  of  consumption 
and  trade  which  yield  the  largest  amount  of  duties,  and, 
finally,  our  national  revenue. 

The  inquiry  into  grants  of  public  lands,  or  the  intro- 
duction of  new  States  into  the  Union,  gives  rise  to  the 
geological  examinations  of  soils,  and  eventually  to  the 
discovery  of  fossils,  ores,  and  metals,  which,  in  printed 
reports,  become  handbooks  of  information  upon  those 
special  subjects. 

The  discussion  of  treaties  makes  them  familiar  with 
international  laws  as  well  as  diplomatic  history.  Memo- 
rials in  regard  to  private  claims  often  bring  to  light  im- 
portant incidents  connected  with  revolutionary  and  other 
events,  and  furnish  materials  for  biography  valuable  to 
our  citizens. 

The  inquiry  as  to  a  standard  for  weights  and  measures 
unfolds  a  wonderful  amount  of  unexpected  knowledge, 
not  only  as  concerns  quantities,  values,  and  weights,  but, 
in  connection  with  the  trade  of  other  countries,  carries  us 
back  to  their  early  dealings,  and  shows  us  the  depend- 
ence upon  and  affinity  between  the  different  steps  for  the 
civilization  of  mankind  throughout  the  world. 

Philosophy,  for  which  man  has  a  natural  tendency, 
becomes  a  prevailing  principle  from  such  causes;  and, 
even  if  a  representative,  when  he  quits  this  arena  in 
which  strife  and  knowledge  are  often  so  much  in  com- 
pany, has  strengthened  his  ties  and  prejudices  of  party, 
he,  nevertheless,  goes  forth  to  the  community  with  much 
and  precise  information  upon  important  subjects  which 
have  engaged  his  especial  attention,  and  becomes  a  well- 
instructed  man  in  the  general  business  of  life. 

Learning  of  any  kind  which  has  an  intellectual  found- 
ation, and  more  particularly  when  associated  with  mo- 


THE  DIGNITY  OF  LABOR. 


33 


rality,  is  of  a  propagative  character,  and  gives  an  appetite 
which  grows  by  what  it  feeds  upon ;  and  hence  we  often 
find  that  men  who  have  begun  as  unpretending  repre- 
sentatives in  halls  of  legislation,  advance  by  the  im- 
pulses of  knowledge  to  still  greater  acquirements,  and 
eventually  become  leaders  in  talent  and  position. 

The  mind  of  Mr.  Pratt  seems  to  have  been  particu- 
larly adapted  to  realize  such  a  condition.  He  was, 
throughout,  an  active  participant  in  congressional  labors, 
and  engaged  not  only  in  co-operating  with  his  colleagues 
and  co-legislators  in  their  general  duties,  but  was  himself 
the  pioneer  and  originator  of  many  serviceable  acts^  in- 
stitutions, and  works. 

In  glancing  through  his  memoirs,  we  are  struck  with 
the  great  variety  of  concerns  in  which  he  bore  an  active 
part;  from  the  report,  as  chairman  of  a  select  commit- 
tee in  favor  of  establishing  a  bureau  of  statistics  and 
commerce,  to  an  inquiry  into  the  condition  of  a  new  ter- 
ritory;  embracing,  in  the  numerous  ramifications  of  labor, 
every  subject  of  polity  pertaining  to  his  day. 

It  has  been  said  that  all  men  have  their  mental  afiini- 
ties;  that  some  pass  unheeded  away  without  having  left 
any  "  footprints  in  the  sands  of  time,"  only  because  the 
period  of  their  sojourning  presented  no  occasions — no 
elective  influences  to  draw  out  their  energies  or  their 
talents ;  while  the  great  are  but  the  creatures  of  oppor- 
tunity; or  who,  having  been  touched  by  the  Ithuriel 
wand,  have  sprung  out  into  light,  brightness,  and  renown. 

Opportunity  is  certainly  a  great  ingredient  in  any 
effort,  and  without  it,  either  ofiered  or  acquired,  no 
voluntary  act  can  well  succeed.  The  characteristic 
traits  of  a  man  are  also  elements  of  his  future ;  but  still, 
it  should  add  to  the  credit  of  the  individual,  who,  culti- 
vating an  understanding  of  his  nature  and  his  latent 


34 


THE  DIGNITY  OF  LABOR. 


abilities,  uses  them  to  advantage  in  that  ^Hide  in  the 
affairs  of  men,  which,  if  taken  at  the  flood,  leads  on  to 
fortune." 

He  was  twice  elected  to  Congress,  and  coming  from 
that  body  with  all  the  advantages  gained  in  such  a  school 
of  varied  studies,  Mr.  Pratt  msLj  be  said  to  have  become 
a  new  man.  He  was  at  first  the  intelligent  novitiate, 
who,  like  one  of  the  travellers  in  Gil  Bias,  merely 
glanced  at  the  inscription  upon  the  wall;  but  now,  re- 
turning among  his  people,  was  like  the  other  scholar, 
carrying  with  him  the  treasures  which  in  his  searchings 
he  found  hid  beneath  the  ambiguous  epitaph  and  the 
stones. 

He  applied  his  new  intelligence  in  various  ways ;  and 
in  the  art  of  tanning,  has  now  competed  for,  and  received 
for  his  products,  the  first  medal  ever  awarded  by  the 
New  York  Institute  in  that  branch  of  manufacture. 
He  endeavors  to  create  as  well  as  to  extend  knowledge. 
He  began  his  efforts  with  the  rising  generation,  that  its 
young  members  might  spread  and  perpetuate  the  fruits 
of  their  studies.  To  accomplish  this,  he  presented  five 
thousand  dollars  to  endow  an  academy  in  the  town  that 
bears  his  name. 

In  consequence  of  the  great  variety  of  useful  offices 
which  he  filled  for  the  public  benefit,  and  without  any 
other  emolument  to  himself  than  honor,  he  was  elected 
a  member  of  several  scientific  and  literary  institutions 
and  colleges ;  and  a  few  years  since  he  closed  his  tan- 
nery, with  great  personal  success,  after  employing  over 
six  millions  of  dollars,  without  a  single  case  of  litiga- 
tion, and  without  loss. 

Fiiiis  coronat  opus. 

The  end  crowns  the  work ;  and  so  have  the  good  results 
of  his  labors  left  a  crown  upon  his  name  more  endear- 


THE  DIGNITY  OF  LABOR. 


35 


ing  to  the  good  man  than  all  the  pomp  and  circumstance 
that  power  alone  or  wealth  could  purchase. 

The  time  was^  and  in  some  degree  still  is,  when  re- 
putation in  honors  was  principally  founded  upon  and 
esteemed  for  distinction  in  literature,  the  fine  arts,  the 
success  of  arms,  the  emblazonments  of  wealth,  and  the 
exemptions,  luxuries,  indulgences,  and  positions  which 
they  respectively  gave.  The  rest,  like  the  hewers  of 
wood  and  drawers  of  water,  who  served  at  the  building 
of  Solomon's  temple,  were  supposed  to  be  sufficiently 
compensated  by  the  daily  penny  paid  for  their  labors. 
No  mark  or  memorial  was  left  upon  the  edifice  of  their 
works;  and  except  in  the  narrow  circle  of  their  indus- 
try, none  knew  of  their  labors  or  .  their  zeal.  In  the 
general  operations  of  society,  it  is  not  to  be  expected  that 
the  mere  ordinary  components  of  that  great  whole  shall 
be  held  in  any  special  remembrance,  either  in  the  pre- 
sent or  the  future,  for  that  would  be  the  exercise  of  a 
weak  and  sici^ly  anxiety  to  elevate  those  who  have  no 
distinctive  merit,  and  to  pull  down  in  some  degree  others, 
so  as  to  create  a  false,  unnatural,  and  unjust  equality. 

But  while  no  such  expectation  could  be  justified,  and 
none  such  will  ever  be  realized,  while  public  opinion  is 
regulated  by  either  good  sense  or  the  dictates  of  justice, 
much  will  be,  as  has  already  been  done  by  the  agency 
of  those  very  qualities,  in  placing  honorable  occupation 
of  labor  upon  the  true  level  of  its  merits. 

The  days  of  chivalry,  founded  upon  the  power  of 
kings  and  nobles — the  empires  of  war  and  victories — 
crusades  of  faith,  and  the  necessary  maintenance  of  the 
followers  of  such  errantries,  as  well  while  they  lasted 
as  in  "the  cankers  of  a  long  peace,"  w^ere  the  beginnings 
of  the  false  distinctions  which  made  idleness  honorable, 
and  left  industry  with  only  the  reward  of  its  own  pro- 
ducts. 


36 


THE  DIGNITY  OF  LABOR. 


Within  the  last  century,  man  has  been  advancing  to 
an  equahty  in  all  his  relations  with  his  fellow-man.  It 
is  not  merely  a  political  change,  but  one  which  belongs 
to  his  whole  range  of  association  and  rights. 

The  toleration  in  religion,  the  extension  of  the  elec- 
tive franchise,  the  repeal  of  tests  of  faith,  the  abolish- 
ment of  imprisonment  for  debt,  the  utilitarian  spirit  of 
the  age,  requiring  every  one  to  contribute  something  of 
value  to  increase  the  general  stock,  have  all  tended  to 
produce  this  equalization.  Now,  men  are  beginning  to 
be  appreciated  for  their  actual  usefulness,  not  for  their 
mere  artificial  position,  based  upon  either  political 
causes  or  the  accidents  of  fortune.  Even  the  iron  ties 
of  party  are  becoming  softened  by  the  spirit  and  solvent 
influences  of  sense  and  improvement.  Those  who  have 
heretofore  tramped  on  in  the  downy  paths  of  public 
honors  and  offices,  enjoying  by  the  permission  and  cre- 
dulity of  the  people  one  high  office  after  another,  not- 
withstanding their  own  doctrine  of  rotation  for  all,  are 
now  looked  upon  as  unprofitable  antiquities,  demagogues, 
creators  of  an  oligarchy  whose  benefits  are  enjoyed  only 
by  themselves,  and  as  a  host  of  politicians,  whose  occu- 
pancy of  places  and  profits,  time  after  time,  amounts  to 
an  exclusive  and  hereditary  right  in  those  who  have  no 
merit  and  contribute  nothing  to  the  common  fund  of 
good. 

These  are  now  becoming  the  subjects  of  scrutiny,  and 
are  likely,  soon,  to  be  swept  away  as  drones  upon  society, 
and 

"  Whistled  down  the  wind,  to  prey  at  fortune/' 

So,  too,  with  the  men  of  patrimonial  wealth  or  riches 
acquired  by  speculation.  Society,  while  giving  them  a 
proper  security  for  all  their  possessions,  begins  to  diminish 
the  respect  formerly  and  lately  paid  to  rnere  property. 


THE  DIGNITY  OF  LABOR. 


37 


The  value  of  wealth,  its  uses,  and  the  protection  of  it, 
are  as  much  appreciated  and  considered  as  ever;  and  so 
they  should  always  be ;  but  there  is  a  separation  of  the 
merits  of  the  man — through  his  talents,  his  industry,  the 
diffusion  of  his  wealth  in  a  general  usefulness — from 
those  which  proceed  solely  from  the  ownership  of  that 
lamp  of  Aladdin,  which  builds  without  earning,  and  ex- 
hibits palaces  and  brightness  that  derive  no  reality  from 
their  possessor. 

It  takes  time  to  accomplish  any  revolution  which  shall 
be  of  permanent  benefit,  and  it  is  proper  it  should  be  so; 
as  improvements  are  worked  out  in  the  progress  of  expe- 
rience which  could  not  be  made  in  a  leap  from  one  con- 
dition to  another. 

The  doctrine  of  a  necessity  for  useful  occupation  in 
all  men  is  a  great  element  in  this  change.  Men  do  not 
begin  to  think  calmly  or  wisely  in  the  turmoil  of  excit- 
ing pursuits.  It  is  only  when  they  are  falling  into  their 
proper  places  in  the  great  community,  and  putting  their 
shoulders  to  the  wheel  to  do  something  useful,  that  they 
perceive  their  relative  positions,  their  obligations,  and 
the  duties  which  belong  to  them  as  integrants  of  the 
whole.  It  is,  therefore,  industry  which  is  the  ground- 
work of  reform  both  moral  and  political;  it  is  the  basis 
of  domestic  virtue,  comfort,  and  plenty,  and  the  producer 
of  what  sustains  a  nation  and  improves  its  condition. 
When  to  this  is  added  education,  its  followers  are  the 
supporters  of  man  in  all  his  conditions,  wants,  advances, 
and  elegances  of  life,  and  are  the  safeguards  of  society. 

These  reflections  rise  spontaneously  from  the  nature 
of  the  subject  we  are  discussing,  as  being  intimately  con- 
nected with  the  career  of  one  whose  doings,  as  a  useful 
citizen,  we  are  considering. 

Biography  is  said  to  be  a  branch  of  history,  and  is  the 


38 


THE  DIGNITY  OF  LABOR. 


reclaiming  or  saving  from  time  of  what  would  otherwise 
be  lost.  If  it  be  creditable  to  perpetuate  the  knowledge 
of  the  deeds  of  men  in  arms ;  of  wars,  that  have  desolated 
the  earth  and  left  misery  and  sighs  to  be  felt  again  in 
after  ages,  by  those  who  deprecate  and  sympathize  while 
they  read;  how  much  more  worthy  an  effort  is  it  to 
record,  in  imperishable  form,  the  good  civic  conduct  of 
those  unpretending  men  who  have  labored  during  their 
lives  for  the  common  weal ;  who  make  in  every  field  two 
blades  of  grass  grow  where  only  one  grew  before ;  -  who 
distribute  among  little  children  the  means  and  the  books 
of  learning,  so  that  the  future  man  may  be  saved  from 
the  evils  of  ignorance  ;  who  endow  and  perpetuate  places 
of  instruction;  who  build  up  manufactories,  and  lasting 
and  ii^creasing  towns;  and,  by  giving  employment  to 
thousands  and  thousands  of  their  fellow-citizens,  lay  the 
foundations  of  occupation  and  industry — the  sources  of 
comfort,  wealth,  and  social  independence  ? 


CHAPTER  III. 

OF  TAN  AND  TANNIN. 

The  name  of  tan  is  applied  to  coarsely-powdered  bark 
containing  a  principle  which  is  the  active  agent  in  the 
tanning  of  hides.  This  component  is  named  tannin^  and 
is  classed  among  the  proximate  principles  of  plants.  As 
the  essential  agent  in  the  process  of  tanning,  we  proceed 
to  make  known  its  chemical  characters,  varieties,  and 
particularly,  its  action  upon  animal  substances  and  oxy- 
salts. 

Dr.  Lewis,  in  examining  nutgalls,  was  the  first  to  ob- 
serve that  it  contained  an  ingredient  which  gave  a  black 
precipitate  with  persalts  of  iron,  and  a  coagulum  with 
isinglass.  Deyeux,  who  also  examined  galls,  considered 
it  a  peculiar  resinous  matter,  but  gave  it  no  name.  Soon 
afterwards,  Seguin,  in  his  researches  on  the  art  of  tan- 
ning, distinguished  it  from  gallic  acid,  with  which  it  is 
so  often  associated  in  vegetable  substances.  This  chemist, 
in  discovering  its  property  of  combining  with  animal 
matters,  and  especially  with  albumen  and  gelatine,  and 
forming  with  them  an  unalterable  insoluble  compound, 
which  is  the  basis  of  leather,  found  the  key  to  the  whole 
theory  of  tanning. 

To  tan  a  skin,  is  to  saturate  it  with  tannin  in  such  a 
manner  as  to  promote  the  slow  combination  of  this  prin- 
ciple with  the  gelatine,  albumen,  and  fibrine  contained  in 


40 


TAN  AND  TANNIN. 


the  former,  so  as  to  form  with  them  a  new  compound. 
This  reaction,  in  the  operation  of  tanning,  does  not  pro- 
ceed spontaneously,  but  is  the  result  of  a  slow  process, 
requiring  great  care  and  skilful  manipulation. 

Tannin  has  been  the  subject  of  investigation  with 
many  chemists,  and,  among  others,  Davy,  Chevreul,  Pel- 
letier,  Lagrange,  Guillot,  Hatchett,  Tromsdorff,  Friedler, 
Eichter,  and  particularly  Proust,  to  whom  we  are  in- 
debted for  our  first  knowledge  as  to  its  nature,  proper- 
ties, and  mode  of  preparation. 

According  to  Wahnlenberg,  it  exists  only  in  perennial 
plants,  and  almost  solely  in  the  permanent  parts;  for 
example : — 

1.  In  the  perennial  roots  of  certain  annual  plants — as 
the  septfoil  and  bistort,  or  snake-weed. 

2.  In  the  bark  of  the  trunks  and  roots  of  nearly  all 
perennial  trees,  especially  in  the  true  cortical  portion,  or 
that  part  next  to  the  liber  and  sap-wood.  Extractive 
predominates  in  the  cellular  integument,  while  the  epi- 
dermis is  usually  destitute  of  both  that  and  tannin. 

3.  In  the  trunks  and  sap  of  many  trees. 

4.  In  the  leaves  of  perennial  plants — but  in  small 
quantities. 

5.  In  the  leaves  of  different  varieties  of  the  oak; 
of  the  tJius  coriaria  (sumach) ;  of  the  arbutus  uva  ursi 
(bear-berry) ;  of  the  arbutus  unedo  (strawberry-tree),  &c., 
in  large  proportion. 

6.  In  the  capsule  of  unripe  fruit  of  the  quercus  robur, 
cegilops  (velonia  oak)  ;  juglans  regia  (walnut) ;  cesculus 
hippocastanum  (horse-chestnut),  and  terminalia  cJiebula, 

7.  In  the  pulp  of  the  fruit  of  the  punica  granatum 
(pomegranate);  rosa  pimpinelUfolia  ;  garcinia  mongostana 
(mangos teen) ;  and  in  the  different  species  of  anona. 

Tannin  has  also  been  found  in  numerous  other  plants, 


PREPARATION  OF  TANNIN. 


41 


of  which  special  mention  will  hereafter  be  made.  At 
present,  however,  it  must  be  noted  that — 

1.  It  is  never  found  to  any  extent  in  the  interior  of 
the  trunk. 

2.  It  does  not  exist  in  poisonous  plants,  or  in  those 
with  a  milky  or  viscid  sap. 

3.  Its  proportion  is  greater  in  young  than  in  old 
plants. 

4.  It  is  transformed  into  a  bitter  principle,  as  the  plant 
increases  in  age. 

5.  It  exists  most  abundantly  in  the  cortical  layers 
of  the  bark,  and  is  usually  altogether  absent  in  the 
epidermis. 

6.  The  proportion  of  tannin  in  barks  varies  with  the 
season,  and  decreases  as  the  severity  of  the  weather 
augments. 

7.  The  two  extremes  of  quantity  are  attained  in 
winter  and  spring. 

PREPARATION  OF  TANNIN  FROM  NUTGALLS. 

The  liquor  or  infusion  of  bark  which  is  used  in  the 
process  of  tanning,  contains  not  only  tannin,  but  gallic 
acid,  extractive,  and  other  principles  of  the  plant,  soluble 
in  water.  In  order  to  present  a  clear  understanding  of 
the  subject,  we  proceed  to  describe  the  various  methods 
by  which  tannin  may  be  separated  from  the  other  con- 
stituents. 

Processes. — 1.  Proust  first  attempted  to  obtain  pure 
tannin  from  nutgalls,  by  macerating  them  in  water,  and 
treating  the  strained  infusion  with  a  solution  of  muriate 
of  tin  until  it  ceased  to  produce  any  precipitate.  The 
yellowish-white  subsident,  tannate  of  oxide  of  tin,  after 
having  been  well  washed,  was  diffused  in  cold  water  and 
4 


j 


42  PREPARATION  OF  TANNIN. 

saturated  with  sulphuretted  hydrogen  gas,  then  filtered 
and  evaporated  to  dryness.  The  evaporated,  desiccated 
filtrate,  said  by  the  author  to  be  pure  tannin,  contains 
also  a  little  gallic  and  hydrochloric  acids,  and  some  ex- 
tractive. 

2.  Deyeux  directs  that  the  aqueous  infusion,  as  ob- 
tained above,  be  concentrated  by  evaporation,  and  pre- 
cipitated with  a  saturated  solution  of  carbonate  of  potassa. 
An  abundant  flaky  precipitate,  of  a  yellowish-white 
hue,  will  subside.  This  precipitate,  which  in  drying 
becomes  a  white  powder,  is  not,  as  the  author  believes, 
pure  tannin,  but  a  compound  of  it  and  gallic  acid  with 
potassa  and  lime,  and  is  only  partially  soluble  in  water. 

3.  According  to  Dize,  when  a  concentrated  infusion  of 
nutgalls  is  treated  with  strong  sulphuric  or  hydrochloric 
acid,  a  curdy  white  precipitate  immediately  falls.  Proust 
regarded  this  precipitate  as  a  compound  of  tannin  with 
the  acid  employed,  which,  for  its  purification,  requires 
only  to  be  washed  with  distilled  water,  then  dissolved  in 
pure  water  and  deprived  of  its  acid  by  saturating  with 
carbonate  of  potassa.  The  tannin  thus  prepared,  however, 
is  not  pure,  but  contains  some  extractive  thrown  down 
by  the  sulphuric  acid,  and  probably,  also,  some  gallic 
acid. 

4.  MeratrGuillot's  method  is  to  precipitate  the  infusion 
of  nutgalls  by  lime-water,  and  then  to  treat  the  precipi- 
tate with  dilute  nitric  or  hydrochloric  acids.  Efferves- 
cence ensues,  the  liquor  assumes  a  darker  shade  of  color, 
and  the  brilliant  brown  residue  is  to  be  separated  by  fil- 
tration. This  tannin  is  not  pure,  but  contains,  according 
to  Davy,  a  compound  of  extractive  with  lime. 

5.  Bouiilon-Lagrange's  method  consists  in  precipitating 
the  infusion  of  galls,  by  carbonate  of  ammonia,  washing 
the  precipitate  with  cold  water,  and  digesting  repeatedly 


V 


PREPARATION  OF  TANNIN.  43 

in  fresh  portions  of  alcohol  of  0.817.  This  process  is  no 
less  defective  than  that  of  Deyeux. 

6.  Tromsdorff  directs  the  infusion  of  three  parts  of 
powdered  galls  in  forty  parts  of  water,  for  three  days,  at 
a  temperature  of  70  to  100°  F.  The  mixture  is  to  be  fre- 
quently stirred  during  the  intervals,  and  then  strained. 
This  manipulation  is  repeated  four  separate  times,  with 
as  many  quantities  of  fresh  water ;  and  when  the  galls 
are  exhausted,  the  strained  liquors  are  to  be  mixed  to- 
gether, evaporated  at  a  gentle  heat,  and  again  strained 
through  a  fine  sieve  in  order  to  separate  extractive  and 
suspended  matters.  Evaporation  is  then  continued  until 
the  filtrate  attains  the  consistence  of  a  jelly,  when  it  is 
to  be  dried  upon  a  stove  and  freed  from  gallic  acid,  by 
successive  washings  with  alcohol  of  .796°.  To  remove 
the  little  mucilaginous  matter  which  it  contains,  Troms- 
dorjQf  advises  that  the  tannin  be  dissolved  in  pure  water, 
and  exposed  to  the  air  until  the  surface  becomes  mouldy, 
when  it  must  be  filtered  and  evaporated  to  dryness.  The 
residue  is  pure  tannin,  containing  some  sulphate  of  lime, 
which  is  to  be  separated  by  dissolving  in  water,  adding 
carbonate  of  potassa,  filtering  off  the  precipitate  and  treat- 
ing with  solution  of  acetate  of  lead,  which  throws  down 
a  pulverulent  compound  of  tannin  and  oxide  of  lead. 
After  washing  and  drying  the  latter,  diffuse  it  in  water, 
saturate  with  sulphuretted  hydrogen  gas,  filter  off  the 
sulphuret  of  lead  which  is  formed,  and  evaporate  the 
filtrate  to  dryness.    The  residue  is  impure  tannin. 

7.  Serturner  employs  an  alcoholic  infusion  of  galls,  and 
precipitates  while  warm,  with  a  solution  of  carbonate  of 
potassa.  After  decanting  the  supernatant  liquid,  the 
residue  is  to  be  washed  with  alcohol,  then  dissolved  in 
water,  the  potassa  to  be  separated  by  sulphuric  acid,  the 
liquor  evaporated,  and  the  residue  treated  with  alcohol. 


44 


PREPARATIOIS"  OF  TANNIN. 


After  precipitating  the  excess  of  sulphuric  acid  by  means 
of  carbonate  of  lime,  the  liquid  is  to  be  filtered  and 
evaporated.  The  residue  is  tannin,  containing  only 
traces  of  gallic  acid. 

None  of  these  different  processes  furnish  tannin  in  a 
state  of  absolute  purity.  Indeed,  its  characteristic  pro- 
perty of  being  soluble  in  water,  and  precipitating  gelatine, 
is  shared  by  other  substances  of  a  totally  different  nature, 
but  which  necessarily  are  comprised  under  the  generic 
title  of  tannin ;  and  the  chemical  properties  of  this  mixed 
substance  are  those  now  referred  to.  For  obtaining  a 
much  purer  tannin,  recent  investigations  have  given  rise 
to  the  following  processes. 

8.  Laubert's  method,  which  possesses  advantages  supe- 
rior to  those  of  any  process  heretofore  given, 
consists  in  infusing  60  grains  of  nutgall  in 
120  grains  of  ether,  for  24  hours,  then  filter- 
ing and  evaporating  the  filtrate  to  dryness. 
The  residue  is  tannin,  containing  a  little  gallic 
acid. 

9.  The  nutgalls,  in  coarse  powder,  according 
to  Pelouze,  are  placed  in  a  long  conical  tube 
(Fig.  1.),  the  narrow  mouth  of  which  is  loosely 
closed  with  cotton  wool;  and  the  tube  thus 
charged  is  made  to  rest  upon  the  rim  of  a  stout 
bottle  as  a  receiver.  Common  sulphuric  ether 
is  then  poured  upon  the  galls,  and  as  it  tra- 
verses the  powder,  it  takes  up  both  the  tannin  and  gallic 
acid.  The  latter,  however,  gives  a  lighter  and  more  fluid 
solution  than  tannin,  and  forms  the  upper  stratum  of 
the  ethereal  solution  which  has  traversed  the  galls  and 
dropped  into  the  receiving  bottle.  The  dense  and  dark 
colored  stratum  below,  contains  tannin.  The  galls  are 
treated  successively  with  new  quantities  of  ether,  until 


PREPARATION  OF  TANNIN. 


45 


they  cease  to  yield  soluble  matter.  The  several  ethereal 
solutions  are  then  mixed  together,  and  poured  into  a 
separating  funnel.  When  the  two  strata  have  formed, 
the  lower  one  containing  the  tannin  is  drawn  off  into  a 
retort,  distilled  to  save  ether,  then  repeatedly  washed  with 
pure  sulphuric  ether,  to  remove  traces  of  gallic  acid,  and 
evaporated  over  a  warm  sand-bath,  or  under  the  receiver 
of  an  air-pump.  Ether  and  water  are  disengaged  during 
the  desiccation ;  the  tannin  swells  up  and  becomes  bulky, 
and  forms  brilliant,  straw-colored,  resin-like  masses. 
The  yield  of  this  process  is  from  35  to  40  per  cent,  of 
tannin,  of  a  very  astringent  taste,  entirely  free  from 
bitterness.  The  ether  for  this  process  must  be  washed 
with  water,  for  tannin  is  not  soluble  in  anhydrous  ether. 

10.  Domine's  method  is  a  modification  of  Pelouze's 
displacement  process,  and  has  the  great  advantage  of 
yielding  a  large  product,  and  of  being  adapted  for 
practice  on  a  manufacturing  scale. 

The  powdered  galls  are  left  for  several  days  in  a  damp 
cellar  to  absorb  moisture.  At  the  end  of  this  time  they 
are  transferred  to  a  wide-mouthed  jar,  and  are  made  into 
thin  paste  with  commercial  ether  of  specific  gravity  .750. 
After  thoroughly  mixing  its  contents  with  a  wooden 
stirrer,  the  vessel  is  to  be  hermetically  closed  and  left  at 
rest  for  24  hours.  Its  contents  are  then  transferred  to  a 
strong  linen  bag,  and  subjected  to  gradual  pressure.  The 
syrupy  liquid  which  exudes  is  caught  in  a  receiver,  and 
evaporated  by  stove  heat  (at  100°  to  110°  F.),  in  shallow 
dishes.  The  tannin  puffs  up  and  dries,  in  the  form  of 
light-colored  resin-like  scales. 

The  marc,  or  pressed  cake,  which  still  retains  some 
tannin,  is  made  to  yield  it  on  being  treated  in  the  same 
manner  as  at  first,  but  with  ether  which  has  been  mixed 
with  six  per  cent,  of  water.    The  expressed  liquid  is 


46 


PREPARATION  OF  TANNIN. 


evaporated  to  dryness  as  before.  The  tannin  obtained 
by  this  process,  as  well  as  by  that  of  Pelouze,  though 
sufficiently  pure  for  the  purposes  of  medicine  and  the 
artS;  contains  a  little  chlorophylle,  volatile  oil,  gallic,  and 
ellagic  acids.  These,  according  to  Guibourt,  may  be  re- 
moved by  repeatedly  agitating  a  mixture  of  equal  parts 
of  the  tannin,  water,  and  washed  ether,  and  then  leaving 
the  bottle  or  containing  vessel  at  rest.  In  due  time,  the 
liquid  will  separate  into  three  strata,  of  which  the  lower 
contains  tannin.  The  latter  being  drawn  off  from  the 
other  two,  will,  on  being  evaporated  and  dried  in  the 
usual  way,  yield  pure  tannin. 

11.  Tannin,  according  to  Mohr,  dissolves  in  ether  of 
0.725,  and  forms  a  syrupy  liquid  which  possesses  the 
peculiar  property  of  not  mixing  with  new  portions  of 
ether;  hence  it  follows  that  tannin  cannot  be  extracted 
by  ether  which  is  not  hydrated. 

The  syrupy  liquid,  upon  being  shaken  with  a  little 
water,  separates  after  repose  into  three  strata.  The 
lower  stratum  is  an  aqueous  solution  of  tannin ;  the  mid- 
dle layer  is  tannin  in  ether,  and  the  upper  one  is  ether 
containing  tannin  and  coloring  matter.  The  addition  of 
a  few  drops  of  alcohol  renders  the  ethereal  solution  more 
fluid;  but  too  large  a  quantity  causes  the  strata  to  com- 
mingle. Mohr,  therefore,  recommends  that  the  ether 
used  for  extracting  tannin  from  galls,  be  mixed  with  al- 
cohol in  the  proportion  of  one  part  to  four  parts  of  ether. 
In  this  way,  by  repeated  treatment  of  the  galls  with 
fresh  quantities  of  alcoholized  ether,  until  they  were 
exhausted,  he  obtained  seventy-eight  per  cent,  of  pure 
tannin. 


IMPURE  TANNIN. 


47 


IMPURE  TANNIN. 

Chemical  Properties. — This  substance  is  a  brown,  in- 
odorous, transparent,  friable,  uncrystallizable  solid,  with 
a  shining  fracture,  and  of  an  acrid  astringent  taste,  but 
sweetish  after  taste.  It  is  heavier  than  water,  reddens 
litmus,  softens  between  the  fingers,  melts  at  a  slightly 
elevated  temperature,  and  is  very  soluble  in  water ;  but 
its  hot  solution,  on  cooling,  drops  a  bright  yellow  pow- 
der. The  solution  is  of  a  brown  color,  and  is  not  affected 
by  exposure  either  to  air  or  moderate  heat.  It  is  slightly 
soluble  in  absolute  alcohol,  but,  according  to  Kichter,  is 
not  entirely  taken  up  by  it  until  the  addition  of  0.10  of 
water.  According  to  Proust,  Deyeux,  and.  Davy,  it  will 
combine  with  oxygen,  but  becomes  altered  in  its  nature 
by  the  union.  Lagrange  says  that  this  absorption  of 
oxygen  generates  gallic  acid.  It  precipitates  albumen 
and  gelatine  from  its  solutions,  and  thus  forms  insoluble 
and  imputrescible  compounds. 

Hydrochloric  and  sulphuric  acids  precipitate  the 
aqueous  solution  of  tannin,  and  the  precipitate,  which  is 
only  slightly  soluble  in  cold  water,  but  soluble  in  hot 
water  and  in  alcohol,  is  generally  a  compound  of  the 
acid  employed,  with  tannin. 

Infusion  of  nutgalls  is  also  precipitated  by  acetic,  ar- 
senic, malic,  oxalic,  and  tartaric  acids,  and  the  precipi- 
tate, after  being  washed  with  cold  water,  and  dissolved 
in  boiling  water,  possesses  all  the  properties  of  tannin. 
Nitric  acid  and  chlorine  readily  destroy  it,  the  first,  by 
converting  it  into  a  brownish-yellow  extractive  matter, 
soluble  in  alcohol.  According  to  Proust,  peroxide  of  tin 
gives  a  similar  reaction.  The  pure  alkalies  and  their 
carbonates  form  with  it  nearly  insoluble  compounds. 


48 


IMPURE  TANNIN. 


Metals,  apparently,  are  without  any  decided  action  upon 
tannin;  but  most  of  the  metallic  and  earthy  oxides  com- 
bine with  and  render  it  insoluble  in  water ;  and  the  same 
oxides  are  insoluble,  or  only  slightly  soluble  in  this 
liquid. 

Thus,  baryta  and  lime-waters  discolor  solution  of 
tannin,  and  precipitate  a  compound  of  tannin  with  the 
earth,  which  is  very  slightly  soluble  in  water,  and  is 
without  action  upon  gelatine.  The  peculiar  precipitate 
of  tannin  with  gelatine  differs  from  the  preceding  in  being 
inseparable  into  its  two  constituents.  In  the  compounds 
of  tannin  with  the  alkalies  or  earths,  the  latter  may  rea- 
dily be  abstracted  by  means  of  an  acid.  By  stirring  re- 
cently precipitated  magnesia  or  alumina  into  a  solution 
of  tannin,  t annates  of  the  earths  are  produced ;  these  are 
insoluble  in  water  and  decomposable  by  acids  which  eli- 
minate the  tannin  and  leave  it  in  solution.  If  infusion 
of  nutgalls  is  treated  with  baryta,  strontia,  or  lime-water, 
the  resulting  precipitate  is  olive-colored,  and  composed 
of  t annate  and  gallate  of  the  earth  united  with  extract- 
ive. By  boiling  the  magnesia  in  the  infusion,  the  preci- 
pitate which  forms  is  dirty  yellow,  insoluble,  and  com- 
posed of  tannin,  extractive,  and  magnesia ;  the  gallate  of 
magnesia,  simultaneously  generated,  remaining  in  solution 
and  imparting  to  it  a  greenish  color.  Albumen  in  small 
proportions  gives  similar  reactions.  In  larger  quantity, 
it  carries  down  all  the  constituents  of  the  infusion.  The 
alkaline  and  earthy  carbonates  also  throw  down  tannin 
and  extractive  from  the  infusion.  The  gallate  formed 
remains  in  solution  and  imparts  a  greenish  color. 

Solution  of  tannin  precipitates  many  of  the  metallic 
salts.  The  strength  of  the  solution,  as  well  as  the  cha- 
racter of  the  salt,  has  an  important  influence  in  the  re- 


VARIETIES  OF  TANNIN. 


49 


action.  In  copper  solutions  the  precipitate  is  olive-green, 
and  in  the  state  of  deutoxide. 

In  those  of  the  protosulphate  of  manganese  it  is  a 
bright  green. 

In  those  of  nitrate  of  mercury  it  is  a  bright  yellow. 

In  those  of  titanium  it  is  blood  red. 

In  those  of  deutoxide  of  iron  it  is  of  a  bluish  hue. 

In  those  of  peroxide  of  iron  it  is  grayish  black. 

Tannin  also  unites  with  various  kinds  of  bitter  prin- 
ciples, with  starchj  gluten,  woody  fibre,  albumen,  caseine, 
the  coloring  matter  of  blood,  osmazome,  animal  mucus, 
&c.,  forming  with  them  insoluble  or  only  slightly  soluble 
compounds. 

By  heat  it  swells  up,  decomposes,  and  when  distilled 
gives  an  acid  liquor,  which  blackens  iron  solutions,  owing 
to  the  formation  and  volatilization  of  pyrogallic  acid. 
A  little  empyreumatic  oil  passes  over  at  the  same  time, 
and  the  residuum  in  the  retort  is  a  bulky  charcoal, 
amounting,  according  to  Proust,  to  .0263  of  the  tannin 
emploj^ed. 

Varieties. — Notwithstanding  the  assiduous  labors  of 
the  numerous  chemists  who  have  investigated  the  sub- 
ject, it  was  a  long  time  before  tannin  was  separated  in  a 
pure  state.  Its  intimate  connection  and  combination 
with  the  extractive  matter  was  the  chief  impediment  to 
its  separation;  and  the  differences  observed  in  specimens 
of  tannin  were  owing  in  part  to  the  nature  and  proper- 
ties of  this  impurity. 

The  least  impure  was  that  extracted  from  grape-seed, 
which  precipitates  gelatine  white.  Gelatine  is  j)recipi- 
tated  yellow  by  tannin  from  sumach ;  deep  red  by  tannin 
from  cinchona;  and  dark  brown  by  that  from  catechu. 

That  from  Brazil  wood,  the  hematine  of  Chevreul, 
forms  with  gelatine  a  precipitate  very  soluble  in  water. 


50 


VARIETIES  OF  TANNIN. 


This  substance  seems  to  partake  equally  of  the  properties 
of  tannin  and  of  extractive  matter. 

Proust  affirms  that  there  are  many  kinds  of  tannin  in 
plants,  just  as  there  are  many  kinds  of  resin;  but  it  is 
possible  that  the  varieties  arise  from  combinations  of  this 
body  with  the  substances  before  mentioned.  It  is  also 
known  that,  in  many  instances,  the  analogy  between 
tannin  and  gallic  acid,  is  such  that  it  is  difficult  to  sepa- 
rate the  former  entirely  from  the  latter;  and,  moreover, 
that  tannin  is  convertible,  under  certain  circumstances, 
into  gallic  acid.  For  example,  an  infusion  of  nutgalls, 
will,  by  protracted  exposure  to  air,  have  its  contents  of 
tannin  mostly  transformed  into  gallic  acid. 

I.  Tannin  from  Gatecliu. — Davy  recommends  the  fol- 
lowing method  of  extracting  tannin  from  catechu.  The 
alcoholic  tincture  is  to  be  evaporated,  and  the  residue 
exhausted  with  water  and  evaporated  to  dryness.  This 
tannin,  though  astringent  at  first,  has  a  sweetish  after 
taste ;  is  soluble  in  alcohol  and  in  w^ater,  with  a  deep 
brown  color,  which  is  heightened  by  ammonia,  potassa, 
soda,  and  magnesia,  without  any  precipitate  being  formed. 
Sulphuric  and  hydrochloric  acids  give  a  light  brown  pre- 
cipitate. This  tannin  does  not  throw  down  the  prot- 
oxide of  iron,  but  precipitates  the  deutoxide  of  an  olive- 
green  color.  Starch,  gluten,  lignin,  gelatine,  albumen, 
&c.,  form  with  it  an  equally  insoluble  precipitate. 

II.  Tannin  from  the  Barh  of  Trees^  Sumach,  0am  Kino, 
&c. — The  astringent  matter  of  vegetables,  though  indis- 
criminately designated  as  tannin,  presents  diffisrences 
which  are  unimportant  as  respects  its  application  to  tan- 
ning purposes,  but  materially  affect  its  chemical  habi- 
tudes. 

Heretofore,  tannin  has  been  classified  into  two  varie- 
ties, one  of  which  is  distinguished  for  giving  a  bluish 


VARIETIES  OF  TANNIN. 


51 


black,  and  the  other  a  dark  green  precipitate  with  per- 
salts  of  iron. 

Berzelius  and  other  chemists  attribute  this  difference 
to  accidental  impurities;  but  Glenhouse  thinks  that  the 
dissimilitude  as  to  the  color  of  the  precipitates  produced 
by  the  tannins  of  different  sources  in  persalts  of  iron,  is 
a  chemical  peculiarity,  indicating  that  they  are  not  iden- 
tical. Moreover,  tannin  from  oak  bark,  and  certain  other 
sources,  unlike  that  from  galls  and  sumach,  does  not  yield 
pyrogallic  acid  by  destructive  distillation. 

The  following  is  a  list  of  the  chief  varieties  of  tannin, 
classified  in  accordance  with  their  relations  to  the  per- 
salts of  iron: — 

1.  Tannin  wliicli  forms  a  Blue  Precipitate  in  Solutions 
of  Persalts  of  Iron. — Tannin  from  nutgalls,  oak,  poplar, 
beech,  hazel,  chestnut,  maple,  horse-chestnut,  cherry, 
apricot,  plum,  elder,  and  other  barks;  sumach  and  log- 
wood, from  the  roots  of  lithruni  salicana^  iris  pseudaco- 
Tus,  geum  urhanum  (Avens) ;  polygonum  histortum  (bis- 
tort) ;  alcliemilla  vulgaris  (ladies  mantle)  ;  from  the 
leaves  of  the  arbutus  uva  ursi  (bear-berry) ;  amothera 
hiennis,  geranium  pratense ;  from  the  husks  of  the  ccesal- 
pina  coriaria;  from  lentils,  &c. 

2.  Tannin  which  forms  a  Green  Precipitate  in  Solutions 
of  Persalts  of  Iron. — Tannin  from  catechu  (juice  of  the 
mimosa  catechu) ;  gum  kino  (juice  of  the  coccoloba  uvi- 
fera)  ;  most  of  the  cinchona  barks ;  horse-chestnut  bark  ; 
the  roots  of  the  rumex  aquaticus  (water  dock) ;  tormen- 
tilla  erecta  (septfoil)  ;  Jcrameria  triandria  (rhatany)  ; 
poll/podium  filix  mas  (male-fern) ;  tea,  and  badian,  a 
species  of  anise;  the  leaves  of  salvia  officinalis  (sage),  and 
of  arnica  montana  (Leopard's  bane),  and  in  date-stones. 

III.  Artificicd  Tannin. — Hatchett  first  discovered  this 
substance  in  1800,  while  experimenting  upon  the  slow 


52 


ARTIFICIAL  TANNIN. 


carbonization  of  plants,  and  in  the  following  year  com- 
municated his  results  to  the  Koyal  Society  of  London. 

First  Variety. — Is  prepared  by  digesting  powdered  char- 
coal with  dilute  nitric  acid,  until  solution  ensues.  The 
proportions  are 

Charcoal     ....      1  part  by  weight. 
Nitric  acid  of  sp.  gr.  1.40   .      5  parts  " 
Water       .       .       .       .    10    "  " 

The  acid  and  water  are  mixed  together,  a  part  is 
poured  upon  the  charcoal,  and  heated  along  w^ith  it  in 
an  open  flask;  lively  effervescence,  and  escape  of  nitrous 
fumes  ensue.  After  two  days,  the  residue  of  the  acid  is 
added,  and  digestion  continued  until  the  entire  solution 
of  the  charcoal.  The  resulting  liquor  is  of  a  deep  brown 
color  and  transparent.  By  evaporation  to  dryness,  it 
leaves  artificial  tannin,  as  a  brown  mass,  containing  a 
slight  excess  of  acid,  which  is  to  be  removed  by  repeated 
treatment  with  water,  and  evaporation  to  dryness  at  a 
gentle  heat.  The  product  amounts  to  1.2  parts.  Any 
greater  quantity  is,  according  to  Hatchett,  owing  to  the 
presence  of  water. 

Chemical  Pro]L>eTties. — Artificial  tannin  is  a  brown  in- 
odorous solid,  with  a  vitreous  fracture,  and  bitter  astring- 
ent taste,  and  is  very  soluble  in  water.  It  dissolves,  also, 
in  alcohol  of  .800,  according  to  Thompson,  and  therein 
differs  slightly  from  ordinary  tannin.  Its  aqueous  solu- 
tion forms,  with  gelatine,  a  brown  precipitate,  insoluble  in 
hot  or  cold  water,  and  lighter  or  deeper  in  color  in  pro- 
portion to  the  strength  of  the  solution.  This  compound 
consists,  according  to  Hatchett,  of  36  tannin  and  64  ge- 
latine in  100  parts.  With  sulphuric  and  hydrochloric 
acids  it  gives  an  abundant  brown  precipitate,  soluble  in 
boiling  water;  the  gelatine  being  precipitated.  Nitric 


ARTIFICIAL  TANNIN. 


53 


acid  dissolves  it  unaltered,  whereas  every  other  variety 
of  tannin  is  decomposed  by  it. 

It  combines  with  potassa,  soda,  and  ammonia,  forming 
solutions  which  deepen  in  color,  and  become  cloudy  in 
a  few  hours.  With  carbonate  of  potassa,  the  behavior 
is  similar,  except  that,  after  a  time,  instead  of  mere 
cloudiness,  a  magma  is  precipitated  from  the  solution. 
If  the  ammoniacal  solution  be  evaporated  to  dryness,  the 
aqueous  solution  of  the  residue  will  not  precipitate  gela- 
tine unless  the  ammonia  retained  in  it  is  first  removed 
by  neutralization  with  hydrochloric  acid.  The  alkaline 
earths y  such  as  lime,  strontia,  baryta,  and  magnesia, 
form,  with  artificial  tannin,  precipitates  very  slightly 
soluble  in  water.  The  metallic  oxides  are  also  thrown 
down  from  their  solutions  by  artificial  tannin,  and  gene- 
rally of  a  chocolate  color. 

Heated  gradually  in  a  retort,  it  yields  at  first  water, 
and  afterwards  nitric  acid,  ammonia,  carbonic  acid,  and 
another  gas,  which  is  probably  nitrogen.  The  residuum 
is  a  charcoal,  amounting  to  0.425  per  cent,  of  the  tannin 
subjected  to  distillation. 

According  to  Chevreul,  this  tannin  is  a  compound  of 
nitrous  or  nitric  acid,  with  a  carbonaceous  matter. 

Hatchett  remarks  that  all  kinds  of  carbon,  whatever 
their  source,  will  yield  artificial  tannin  by  the  action  of 
nitric  acid.  Other  substances  will  also  furnish  it.  Vege- 
table carbon,  however,  is  the  most  convenient  and  prolific 
source. 

Second  Variety. — This  is  prepared  by  treating  indigo, 
resins,  and  similar  substances  rich  in  carbon,  with  nitric 
acid,  in  the  manner  above  directed.  The  solution  of 
indigo  thus  made,  gives  a  very  bitter  orange-colored 
residue,  soluble  in  water.    It  forms  an  insoluble  com- 


54 


ARTIFICIAL  TANNIN. 


pound  with  gelatine,  reacts  with  metallic  salts  more  feebly 
than  tannin,  and  contains  nitric  or  nitrous  acid. 

Third  Variety. — Is  obtained  by  dissolving  camphor  or 
one  of  the  resins  in  sulphuric  acid,  and  digesting  until 
the  solution  becomes  black.  Cold  water  is  then  added. 
The  black  powder  which  precipitates  is  to  be  digested 
in  alcohol  and  the  solution  evaporated  to  dryness.  The 
brown  residue  is  soluble  in  alcohol  and  water,  forms  an 
insoluble  precipitate  with  gelatine,  and  reacts  feebly  with 
persulphate  of  iron.  According  to  Chevreul,  this  variety 
of  tannin  contains  hyposulphuric  acid. 

IV.  Tannin  from  various  Sources. — Having  shown  that 
many  substances  by  combination  with  certain  acids  yield 
either  natural  or  artificial  tannin,  it  is  more  than  probable 
that  tannin  is  not  an  immediate  vegetable  principle,  but  a 
true  compound  of  a  peculiar  substance,  and  an  acid,  with 
more  or  less  of  extractive  matter,  and  thus  constituting 
the  different  varieties  of  natural  tannin. 

1;  Thus  the  tannin  from  nutgalls,  oak  bark,  sumach, 
willow,  horse-chestnut,  cherry,  &c.,  is  united  with  a 
greater  or  less  amount  of  gallic  acid,  from  which  it  is 
difficult  to  separate  it  entirely.  The  older  the  plant,  the 
smaller  the  quantity  of  tannin,  and  consequently  the 
more  of  gallic  acid  is  contained  in  it. 

2.  The  artificial  tannins  are  always  combined  with 
nitric  or  sulphuric  acid. 

3.  It  is  also  in  the  acid  fruits,  such  as  the  pomegranate, 
that  tannin  exists ;  and  generally,  associated  with  gallic 
acid,  and  the  vegetable  acid  of  the  fruit,  which  possibly 
may  be  the  source  of  the  tannin. 

Chemists  reckon  four  varieties  of  tannin. 

1.  Natural  tannin^  comprising  several  species  origi- 
nating from  the  different  proportions  of  extractive  and 
gallic  acids. 


PURE  TANNIN". 


55 


2.  Artificial  tannin,  obtained  by  the  action  of  nitric 
acid  upon  charcoal. 

3.  Artificial  tannin,  obtained  by  the  action  of  nitric 
acid  upon  indigo  and  the  resins. 

4.  Artificial  tannin,  obtained  by  the  action  of  sulphuric 
acid  upon  the  resins  and  camphor. 

PURE  TANNIN. 

Chemical  Properties, — Pure  tannin  is  colorless,  inodor- 
ous, very  astringent,  and  largely  soluble  in  water.  This 
solution  reddens  litmus,  and  hence  its  acid  reaction  has 
procured  for  it  the  name  of  tannic  acid.  Moreover,  it 
decomposes  the  alkaline  carbonates  with  effervescence, 
and  as  the  solution  forms  with  most  of  the  metallic  solu- 
tions, precipitates  which  are  true  tannates,  it  is  entitled 
to  be  ranked  among  the  acids.  Solutions  of  the  proto- 
salt  of  iron  do  not  disturb  this  solution,  unless  both  are 
concentrated;  but  those  of  the  peroxide  give  an  abund- 
ant blue  precipitate.  This  precipitate  is  formed  only  by 
the  excess  of  acid,  for  the  portion  first  added  is  decom- 
posed in  reducing  the  peroxide  to  protoxide  of  iron,  and 
the  precipitate  which  is  eventually  produced,  is  a  mixed 
compound  of  proto  and  per  tannate  of  iron. 

Alcohol  and  ether  dissolve  tannin,  but  by  no  means 
so  largely  as  water;  their  solvent  power  decreasing  in 
proportion  as  they  approach  the  anhydrous  state.  These 
solutions,  by  prolonged  exposure  to  the  air,  absorb  oxygen 
and  deposit  crystals  of  gallic  acid.  Apotlieme  is  also  an 
accompanying  product  of  the  slow  conversion  of  tannin 
and  tanning  solutions  by  exposure  to  air.  It  is  a  dark 
brown  substance  soluble  in  water,  and  is  the  source  of 
the  objectionable  color  of  several  kinds  of  leather. 

As  before  observed,  tannin  has  not  been  obtained  in  a 


56 


PURE  TANNIN. 


crystallized  form,  although  attempts  have  been  made  with 
various  solvents.  When  burned  upon  platinum  foil,  it 
leaves  no  residue. 

A  concentrated  solution  gives  an  abundant  white  pre- 
cipitate, with  sulphuric,  hydrochloric,  nitric,  phosphoric, 
and  arsenic  acids ;  but  not  wdth  oxalic,  tartaric,  lactic, 
acetic,  citric,  succinic,  and  selenious  acids.  Nor  does 
sulphurous  acid  gas  cause  a  precipitate.  By  being  heated 
with  nitric  acid,  tannin  is  rapidly  decomposed  with  the 
evolution  of  nitrous  fumes,  and  converted  into  crystals 
of  oxalic  acid. 

The  salts  of  cinchona,  quinia,  brucia,  strychnia,  codeia, 
narcotina,  and  morphia,  form,  with  solution  of  tannin, 
white  precipitates,  very  soluble  in  acetic  acid,  but  only 
slightly  in  water. 

Poured  into  solutions  containing  an  excess  of  gelatine, 
it  produces  a  white  opaque  precipitate,  soluble,  particu- 
larly by  heat,  in  its  own  liquid.  On  the  contrary,  when 
the  tannin  predominates,  the  precipitate,  instead  of  dis- 
solving when  heated,  collects  into  grayish  elastic  coagula. 
In  either  case  the  liquid,  when  filtered,  is  colored  deeply 
blue  by  the  persalts  of  iron. 

The  insolubility  of  the  compound  of  tannin  with  gela- 
tine is  no  guarantee  of  the  purity  of  the  former  or  of  the 
absence  or  presence  of  gallic  acid.  Pelouze  determines 
these  facts  by  leaving  the  suspected  tannin  in  contact  with 
a  piece  of  hide  freed  from  hair  and  prepared  for  the  tan- 
vat.  After  a  time,  during  which  the  liquid  is  repeatedly 
stirred,  it  is  filtered,  when,  if  the  tannin  is  pure,  there 
is  no  residue  left  uncombined  with  the  hide ;  and  the  water 
used  as  menstruum  does  not  give  the  slightest  color  with 
salts  of  iron,  and  moreover  is  tasteless,  and  evaporates 
without  residue.    If  the  tannin  contains  the  slightest 


PURE  TANNIN. 


57 


trace  of  gallic  acid^  then  the  liquid  is  perceptibly  tinged 
of  a  blue  color  by  the  salts  of  iron. 

Gelatinous  alumina,  when  mixed  with  solution  of  tan- 
nin, is  rapidly  absorbed,  and  produces  an  insoluble  com- 
pound. The  supernatant  liquor  does  not  color  the  salts 
of  iron  blue.    Gallic  acid  behaves  similarly. 

At  the  temperature  of  boiling  oil  (630°  F.),  tannin  is 
decomposed  into  water,  carbonic  acid,  and  an  abundant 
residue  of  metagallic  acid,  or,  in  other  words,  the  same 
products  as  from  gallic  acid.  But  with  tannin,  whatever 
the  care  observed  in  maintaining  the  temperature  uni- 
formly at  as  low  a  degree  as  will  suffice  for  the  reaction, 
the  generation  of  a  notable  quantity  of  metagallic  acid 
is  unavoidable. 

Tannin,  as  formerly  prepared,  in  an  impure  form,  was 
composed,  according  to  Berzelius,  of 

Carbon  52.69 

Oxygen  43.45 

Hydrogen  3.86 

100.00 

The  more  recent  analyses  of  pure  tannin,  by  Pelouze, 
prove  that  its  composition  is  CisHgOig  = 

Carbon  51.77 

Hydrogen  3.98 

Oxygen  44.25 

100.00 


5 


CHAPTER  IV. 


GALLIC  ACID. 

Gallic  acid  was  first  obtained  hy  Scheele,  in  1786, 
from  nutgalls,  whence  its  name.  It  exists  also  in  the 
cypress  nut,  arnica  flowers,  white  hellebore,  meadow  saf- 
fron (colchicum  autumnale)^  and  in  a  large  number  of 
astringent  barks,  as  a  concomitant  of  tannin,  but  not  in 
any  considerable  quantity.  To  be  obtained  abundantly, 
the  assistance  of  active  chemical  agents  is  necessary. 

Preparation. — 1.  Scheeles  Process. — A  strong  aqueous 
infusion  of  nutgalls  is  made,  and  after  being  filtered, 
is  exposed  for  some  time  at  70°,  to  the  action  of  the 
atmosphere.  Gradual  fermentation  ensues,  and  the 
tannin  is  more  or  less  transformed  into  gallic  acid;  a 
mouldy  scum  being  simultaneously  generated.  After 
two  months  the  scum  is  removed,  and  the  yellow  or 
grayish  deposit  at  the  bottom  of  the  vessel  is  separated 
from  the  liquid,  dissolved  in  boiling  water,  filtered, 
and  cautiously  evaporated  and  set  aside,  in  order  that 
the  gallic  acid  may  crystallize  upon  cooling.  Solution 
in  water,  filtration  through  animal  charcoal,  and  recrys- 
tallization,  will  remove  all  impurities  from  the  acid. 

2.  Fiedlers  Process, — Three  hundred  grains  of  pow- 
dered nutgalls  are  to  be  boiled  in  five  thousand  grains  of 
water,  and  filtered.  To  the  filtrate,  add  six  hundred 
grains  of  alum,  the  alumina  of  which  has  been  pre- 


GALLIC  ACID. 


59 


cipitated  by  carbonate  of  potassa;  stir  the  mixture,  leave 
it  at  rest  until  the  next  day,  and  then  filter.  Wash  the 
precipitate  with  warm  water,  until  what  passes  through 
ceases  to  blacken  sulphate  of  iron;  mix  the  wash 
liquors,  concentrate  by  careful  evaporation,  and  set 
aside.  The  gallic  acid  crystallizes,  on  cooling,  in  fine 
needles. 

3.  Ures  Process. — Add  muriate  of  tin  to  a  strong  in- 
fusion of  nutgalls  until  it  ceases  to  give  a  precipitate; 
filter,  diffuse  the  precipitate  in  water,  treat  with  a  stream 
of  sulphuretted  hydrogen  gas ;  filter,  and  evaporate  the 
filtrate.    Gallic  acid  will  crystallize  out  on  cooling. 

4.  Braconnofs  Process. — Powdered  nutgalls  are  to  be 
drenched  with  water  and  exposed  to  the  air  at  a  tempera- 
ture of  from  70°  to  75°.  A  quiet  reaction  ensues,  and 
the  mixture  becomes  pasty.  This  paste  is  subjected  to 
pressure,  and  is  then  heated  with  boiling  water,  which 
dissolves  out  the  gallic  acid  and  yields  it  in  impure  crys- 
tals by  evaporation.  It  may  be  freed  from  color  by 
solution  in  water,  filtering  through  bone-black,  and  re- 
crystallization. 

5.  Kent's  Process. — E.  N.  Kent  obtained  gallic  acid 
from  ink  which  had  been  exposed  to  the  air,  by  agitating 
it  with  an  equal  volume  of  sulphuric  ether  devoid  of 
alcohol,  allowing  the  two  strata  of  liquids  to  separate  by 
repose,  decanting  the  ethereal  stratum,  and  distilling 
nearly  to  dryness.  The  residue,  on  cooling,  deposits 
crystals  of  gallic  acid.  The  ether,  in  this  process,  takes 
up  gallic  acid  to  the  exclusion  of  the  other  constituents 
of  the  ink. 

6.  WetherilTs  Process. — Thirteen  drachms  of  dry  tan- 
nin are  to  be  boiled  with  twenty-two  fluidounces  of  sul- 
phuric acid  of  1.84°,  diluted  with  four  times  its  volume 
of  water.    Crystals  of  gallic  acid  are  deposited,  the  pro- 


60 


GALLIC  ACID. 


duct  amounting  to  upwards  of  80  per  cent,  of  the  tannin 
employed.  This  process  is  founded  upon  the  hypothesis 
that  gallic  acid  differs  from  tannin  only  in  containing 
water.  The  separation  of  this  constituent  is  effected;  in 
the  above  process,  by  the  sulphuric  acid. 

Properties. — This  acid,  when  pure,  is  in  very  white 
silky  needles,  which  are  unalterable  in  the  air.  It  is 
inodorous,  of  an  acid,  slightly  astringent,  but  sweetish 
taste,  and  reddens  litmus.  It  dissolves  in  100  parts  of 
cold  and  in  3  of  hot  water.  This  solution,  by  exposure, 
becomes  covered  with  mould,  and  spontaneously  decom- 
poses and  turns  brown.  It  is  also  soluble  in  4  or  5  parts 
of  cold,  and  in  1  part  of  hot  alcohol.  The  spirituous 
solution,  though  more  permanent  than  the  aqueous,  also 
yields  to  the  decomposing  action  of  the  atmosphere,  as 
well  as  to  that  of  light ;  for,  even  if  the  containing  vessel 
be  closely  stoppered,  the  liquid  soon  becomes  colored. 
By  a  gentle  heat  it  may  be  sublimed,  and  it  is  this  mode 
which  Deyeux  recommends  for  obtaining  it  pure.  At  a 
red  heat,  it  is  partially  decomposed.  The  aqueous  solu- 
tion  of  gallic  acid,  upon  treatment  with  potassa,  soda,  or 
ammonia,  assumes  a  reddish-yellow  color,  which  turns 
to  deep  brown  upon  exposure  to  the  air,  probably  from 
absorption  of  oxygen.  By  the  use  of  alcohol  as  a  solvent, 
and  certain  precautions,  definite,  crystallized,  and  soluble 
compounds  of  the  acid  with  these  bases  may  be  formed. 
If  the  acid  is  associated  with  tannin,  it  decomposes  nearly 
all  the  permanent  metallic  salts.  With  baryta,  strontia, 
and  lime,  it  forms  slightly  soluble  compounds.  Its 
affinity  for  magnesia  is  very  strong,  and  the  compound 
which  it  forms  with  that  earth  is  insoluble  in  w^ater,  but 
soluble  in  excess  of  acid.  Gallic  acid  is  also  neutralized 
by  alumina. 


GALLIC  ACID. 


61 


Gallic  acid  gives 

An  orange-yeUow  precipitate  with  the  soluble  salts  of 
mercury. 

A  hrown  precipitate  with  the  soluble  salts  of  copper, 
A  lemon-yellow  precipitate  with  the  soluble  salts  of 
hismutJi, 

A  loJiite  precipitate  with  the  soluble  salts  of  lead, 
A  deep  hlue-hlach  precipitate  with  the  soluble  salts  of 
'peroxide  of  iron. 

This  last  per-compound  of  iron  is  the  basis  of  black  ink 
and  of  black  dyes.  Its  characteristic  behavior  with  iron 
renders  gallic  acid  an  efficient  reagent  for  the  detection 
of  salts  of  that  metal.  With  protosalts  of  iron,  it  gives  no 
color.  Pure  gallic  acid,  when  free  from  tannin,  does  not 
produce  any  change  in  solutions  of  gelatine  or  alkaline 
salts.  It  is  consequently  of  no  value  for  tanning  pur- 
poses, and  proper  precautions  must  be  observed  to  pro- 
tect the  tan  liquor  from  decomposing  influences,  so  as  to 
prevent  the  loss  that  would  accrue  by  the  conversion  of 
its  tannin  into  gallic  acid,  or  other  equally  valueless  de- 
rivatives. The  tannin  from  galls  and  sumach  is  particu- 
larly susceptible  in  this  respect;  the  malic  acid  of  the 
latter  serving  as  a  ferment  to  promote  the  transforma- 
tion. The  only  service  of  gallic  acid  in  tanning  is  to 
swell  the  hides  which  have  been  cleansed  in  lime-water, 
and  thus  facilitate  the  penetration  of  the  ooze.  For  this 
purpose,  they  are  suspended  in  spent  liquors,  which 
always  contain  gallic  acid,  and  afterwards  transferred  to 
the  strong  liquor.  Sulphuric  acid  would  answer  the 
same  purpose,  and  is  frequently  employed. 

By  dry  distillation  in  a  retort  over  an  oil  bath,  heated 
cautiously  to,  and  maintained  at  420°,  it  gives  off  pure 
carbonic  acid  gas,  and  a  white  sublimate  of  pyrogallic 


62 


ELLAGIC  ACID. 


acid  in  brilliant  crystalline  plates,  which  line  the  dome 
of  the  retort.  No  water  or  empyreumatic  matters  are 
formed;  nor  is  there  any  residue  remaining.  If,  how- 
ever, the  heat  of  the  bath  be  rapidly  increased,  so  as  to 
make  the  oil  boil,  carbonic  acid  is  given  off  instead  of 
the  crystalline  sublimate ;  water  distils  over,  and  a  bril- 
liant black  mass  remains  in  the  retort.  This  latter  re- 
sembles carbon  in  appearance,  and  is  tasteless  and  inso- 
luble, and  being  a  true  acid  has  been  termed  by  Pelouze 
the  metagallic. 

The  composition  of  crystallized  gallic  acid,  according 
to  Pelouze,  is  C7H305+HO= 

Carbon  50.10 

Hydrogen  .  .  .  .  3.64 
Oxygen  ....  46.26 

100.00 

ELLAGIC  ACID. 

This  title  has  been  given  by  Braconnot  to  a  substance 
simultaneously  formed  with  gallic  acid,  by  the  pro- 
tracted exposure  of  moistened  galls  to  contact  with  air. 
Gallic  acid  is  dissolved  out  with  boiling  water;  and  the 
residue  treated  with  dilute  potassa  lye  to  extract  the 
ellagic  acid.  Dilute  hydrochloric  acid  added  to  this  lye 
throws  down  the  acid  in  yellow  powder.  It  is  tasteless, 
almost  insoluble,  slightly  reddens  litmus,  and  forms 
crystalline  salts  with  the  alkaline  bases. 

The  following  is  a  table  of  the  various  derivatives  of 
tannic  acid  (C18H8O12) : — 

1.  Oxy tannic  acid  (CisHgOu),  generated  by  the  com- 
bined action  of  potassa  and  the  atmosphere. 


ELLAGIC  ACID. 


63 


2.  MelanoianniG  acid  (CuHeOg),  generated  by  the  joint 

action  of  potassa,  air,  and  heat. 

3.  Melanogallic  acid,  Metagallic  (C12H3O3),  by  the  sudden 

action  and  continuance  of  a  temperature  of  480°. 

4.  Gallic  acid  (C7H3O5),  by  the  action  of  air  and  water 

alone,  or  by  the  joint  action  of  heat,  water,  and 
sulphuric  acid. 

5.  Ellagic  acid  (C7H2O4),  by  the  action  of  air  and  water. 

6.  Paraellagic  acid  (C7H2O4),  by  the  joint  action  of  water, 

sulphuric  acid,  and  a  temperature  of  285°. 

7.  Pyrogallic  acid  (CeHgOa),  by  sublimation  of  galls,  or 

of  gallic  acid  at  410°. 

As  this  acid  plays  no  part  in  tanning,  it  is  unnecessary 
to  extend  the  description.    Pelouze's  formula  for  it  is 


C^HA+HO^ 


Carbon 
Hydrogen  . 
Oxygen 


100.00 


CHAPTER  V. 
EXTRACTIVE. 

The  opinion  of  chemists  generally  is  adverse  to  the 
consideration  of  extractive  as  an  immediate  principle  of 
plants.  It  is  rather  a  mixture  of  acid  and  of  coloring 
and  nitrogenous  matters.  Albumen,  tannin,  starch, 
gluten,  &c.,  may  also  be  constituents  according  to  the 
source  of  the  extractive.  Strictly  speaking,  extractive 
does  not  exist  as  such  in  vegetable  substances,  but  is 
generated  by  the  action  of  heat,  the  oxygen  of  the  air, 
or  by  chemical  agents  upon  the  constituents  of  the  plant. 
Consequently,  it  is  not  of  uniform  composition,  but  va- 
ries in  its  chemical  characters. 

The  older  chemists  applied  the  term  extracf  to  the 
incongruous  mixture  obtained  by  evaporating  the  juice 
or  aqueous  infusion  of  plants  to  inspissation.  The  ap- 
plication of  the  term  was  afterwards  extended  to  the 
residue  resulting  from  the  evaporation  of  alcoholic  or 
ethereal  solutions;  but  it  is  now  limited  to  a  peculiar 
body  contained  in  these  extracts,  and  is  still  considered 
to  be  an  independent  principle  by  a  large  number  of 
chemists. 

Hermbstadt  directed  the  evaporation  to  dryness  of  an 
infusion  of  saffron,  as  his  method  of  obtaining  it  in  a  state 
of  purity ;  but  the  product  thus  obtained  could  not  be 
other  than  an  aqueous  extract. 


EXTRACTIVE. 


65 


The  extractive  principle  is  soluble  in  water,  and  the 
liquid,  which  is  always  colored,  yields  by  evaporation  a 
deep  brown,  brittle  extractive  of  a  bitter  taste,  soluble  in 
alcohol,  but  almost  insoluble  in  ether.  When  oxidized, 
it  is  insoluble  in  water ;  chlorine  precipitates  it  from  its 
solutions  in  dark  yellow  flakes,  termed  by  Saussure 
Apotheme;  it  is  also  precipitated  by  strong  sulphuric  and 
hydrochloric  acids.  With  most  of  the  metallic  salts,  it 
forms  insoluble  compounds  ;  and  by  distillation  yields  an 
ammoniacal  liquor. 

Deyeux  and  Yauquelin  found  it  in  the  sap  of  all  the 
trees  which  they  examined.  It,  or  rather  its  constitu- 
ents, forms  a  part  of  the  barks  of  all  trees  which  have  as 
yet  been  analyzed.  Davy  found  it  in  numberless  trees, 
and  especially  in  the  bark  of  the  oak  of  the  Leicester 
and  common  willows,  Spanish  chestnut,  elm,  &c.  It  ex- 
ists also  in  the  catechu,  senna,  and  Peruvian  bark,  &c. 
In  fact,  according  to  Thompson,  extractive  is  always  an 
associate  of  tannin.  Still,  we  adhere  to  the  opinion  that 
extractive  is  a  compound  of  several  vegetable  principles, 
varying  in  character  with  the  plant  whence  it  is  obtained, 
and  thus  more  or  less  influencing  the  operation  of  tan- 
ning. 


CHAPTER  VI. 


TANNING  MATERIALS. 
TANNING  JUICES. 

The  sap  of  a  plant  is  its  life-juice,  which  starts  into 
motion  as  soon  as  the  genial  warmth  of  spring  arouses  it 
from  its  winter  torpor.  It  ascends  from  the  roots  and  is 
the  source  of  all  the  secretions  of  the  plant.  In  its  ori- 
ginal and  natural  state,  it  consists  of  gaseous  and  earthy 
matters  dissolved  in  water;  but  in  coursing  the  permeable 
tissue  or  sapwood  of  the  trunk,  it  takes  up  other  sub- 
stances. These  serve  as  nourishment  to  the  plant,  which 
assimilates  them  by  the  action  of  its  vital  chemistry. 
The  sap  is  a  clear,  transparent,  colorless  liquid,  some- 
times insipid,  occasionally  sweet,  and  nearly  always  acid. 
Confined  in  a  bottle,  its  fermentation  becomes  so  active 
as  to  drive  out  the  cork;  it  has  then  acquired  acidity, 
and  is  more  or  less  turbid.  By  exposure  to  air,  it 
becomes  yellow  and  brown,  and  deposits  flakes  of  an 
albumino-extractive  character. 

Vauquelin  and  Deyeux,  who  made  numerous  analyses 
of  saps,  found  tannin  in  the  following  : — 

1.  In  the  sap  of  the  beech-tree  [fagus  sylvatica).  The 
analyses  were  made  in  March  and  at  the  end  of  April. 
During  the  latter  month,  it  was  of  a  fawn  red  color, 
had  a  tan-like  taste,  and  slightly  reddened  litmus.  In 


CATECHU. 


67 


either  month  it  was  composed  of  much  water ;  tannin 
precipitating  sulphate  of  iron  black;  mucus  and  ex- 
tractive matters ;  acetates  of  potassa  and  alumina,  and 
gallic  and  acetic  acids. 

Tannin  is  also  found  in  the  sap  of  the  oak,  and  pro- 
bably in  that  of  many  other  trees. 

As  soon  as  the  sap  reaches  the  leaves,  it  undergoes 
various  transformations,  and  is  converted  into  liquids 
which  circulate  in  vessels  returning  towards  the  roots. 
These  liquids  differ  in  their  nature.  Some  are  saccharine, 
and  others  mucilaginous,  gummy,  resinous,  oily,  milky, 
astringent,  &c. 

A  large  number  of  these  vegetable  saps  contain  tannin, 
and  we  will  name  two  which  have  been  analyzed. 

1.  The  sap  of  an  old  horse-chestnut,  dried  upon  the 
bark,  and  having  the  appearance  of  chalk,  was  found  to 
contain  tannin,  which  gave  a  green  color  with  the  sul- 
phate of  iron. 

2.  The  inspissated  juice  of  the  cachou,  known  under 
the  names  of  catechu,  terra  jajponica, 

CATECHU,  TERRA  JAPONICA,  01^  CUTCH. 

This  is  a  product  of  the  fruit  of  the  mimosa  catechu^ 
obtained  by  evaporating  the  decoction.  Catechu  is  im- 
ported from  Calcutta,  and  several  varieties  are  found  in 
commerce. 

1.  Cahe  Catechu. — This  variety  is  brought  to  us  in 
circular,  plano-convex  cakes,  with  rounded  edges,  the 
size  and  weight  of  which  vary  from  two  to  six  inches 
in  diameter,  and  from  several  ounces  to  two  pounds. 
Externally  they  are  dark  brown  and  smooth,  internally 
always  brown,  frequently  dark,  sometimes  blackish,  and 
rarely  of  a  light  yellow  or  chocolate  color,  and  more  or 


68 


CATECHIT. 


less  cellular.  The  fracture  is  smooth  in  the  compact 
parts,  and  rough  or  spongy  in  other  portions.  This 
variety  is  often  of  good  quality. 

2.  Pegu  Catechu. — This  derives  its  name  from  the 
province  in  Burmah,  whence  it  is  obtained.  It  comes 
in  masses  of  one  hundred  pounds'  weight,  but  as  met 
with  in  the  shops  is  in  angular  irregular  fragments/ in 
double  layers,  with  leaves  intervening.  This  is  an 
excellent  quality  of  catechu,  and  is  remarkable  for  its 
compactness,  shining  fracture,  and  deep  brown  color. 

3.  Bengal  Catechu  is  originally  in  the  form  of  quad- 
rangular cakes  about  two  or  three  inches  long  and  broad; 
but  as  found  in  market,  is  in  fragments.  It  is  rusty 
brown  externally,  and  dark  brown  or  brownish  gray 
internally,  and  has  a  rough,  dull  fracture. 

4.  Bombay  Catechu  occurs  in  globular  lumps,  of  the 
size  of  an  orange,  flattened,  and  two  pieces  generally 
adhering  together.  It  resembles  the  Bengal  catechu  in 
color  and  fracture. 

5.  Gambir, — This  is  an  astringent  extract,  imported 
from  the  East  Indies  under  the  name  of  ferra  japonica. 
It  is  prepared  from  the  uncaria  gambir ,  or  nauclea  gambir^ 
and  contains,  according  to  Esenbeck,  from  36  to  40  per 
cent,  of  tannin.  It  is  in  cubes,  with  sides  of  an  inch  square. 
External  color  deep  yellow  or  reddish  brown,  but  paler 
within;  fracture  dull  and  earthy;  taste  bitter  and 
astringent,  but  subsequently  sweetish.  Is  porous,  lighter 
than  water,  wholly  soluble  in  it  by  boiling;  swells  up 
when  heated,  and  leaves  but  little  ash  when  burned. 

6.  Arecha  Catechu, — Prom  the  arecha  catechu,  a  palm 
of  India.  Obtained  by  evaporating  a  decoction  of  the 
nuts.  There  are  two  varieties,  viz.,  Jcassu,  black,  astring- 
ent, and  intermixed  with  husks;  and  couri/,  which  is 
yellowish  brown  with  an  earthy  fracture.    The  latter  is 


KINO. 


69 


made  from  the  nuts,  which  have  already  been  partially 
exhausted  in  yielding  the  former. 

As  found  in  commerce,  catechu  is  often  adulterated 
with  starch,  which  is  readily  detected  by  treatment  with 
water,  which  will  dissolve  the  catechu  and  leave  the 
starch  as  residue.  This  residue,  moreover,  gives  a  jelly 
upon  being  boiled  with  water.  Davy's  analyses  of  cate- 
chu give  the  following  results  : — 

Bengal  Catechu.    Bombay  Catechu. 


Tannin         ...  97  109 

'ExtrsiGtiYe  {Catechuic  acid)  73  68 

Mucilage       ...  16  13 

Kesidue  of  lime  and  alumina  14  10 


200  200 

Cooper  found  in  cuich,  which  is  a  commercial  name 
for  catechu, 

Water   12.8 

Tannin   47.7 

Extractive  matter    .       .       .       .  9.2 

Gummy                 ....  13.6 

Eesinous                .       .       .       .  6.8 

Insoluble  residue     .       .       .       .  9.4 


99.5 

The  white  coating  which  invests  the  leather  made 


with  decoction  of  catechu,  is  catechuine  or  tanningenic 
acid,  one  of  the  constituents  of  the  drug.* 

KINO. 

This  is  the  inspissated  juice  of  certain  plants,  met  with 
in  commerce,  in  brown,  dry,  shining  masses  or  grains. 

*  Cooper,  Phil.  Mag.  3d  ser.  xxiv. 


70 


VEGETABLE  FUNGI. 


There  are  several  varieties:  1.  African  kino,  from  the 
^terocarpus  erinaceus;  2.  Asiatic  kino,  from  the  'ptero 
carpus  marsupmm  ;  3.  American  kino,  from  a  decoction 
of  the  fibrous  wood  of  coccoloba  uvifera.  The  African, 
which  is  the  most  common  kind,  differs  from  the  rest  in 
coming  in  small,  angular,  glittering,  black  granules, 
giving  a  beautiful  brownish-red  powder.  It  consists  of 
seventy-five  parts  of  tannin  and  extractive,  twenty-four 
parts  mucilage,  and  one  part  lignin  ( Vauquelin) .  Kino- 
tannin  forms  a  red  mass,  and  yields  no  pyrogallic  acid 
in  dry  distillation. 

VEGETABLE  FUNGI,  OR  EXCRESCENCES  CONTAINING  TANNIN. 

Nutgalls. — This  material  is  so  rich  in  tannin  that  it 
merits  an  extended  notice.  The  name  of  nutgall  ap- 
plies to  the  round  excrescences  upon  the  quercus  infec- 
toria.  They  are  produced  by  the  puncture  of  an  insect 
called  by  LinnaBus  cynips  quercus  folii^  and  by  Geoffrey, 
diplolepsis  gallce  tinciorice.  These  excrescences,  which  re- 
sult from  a  morbid  action,  induced  as  above  stated,  have 
their  source  in  the  juice  of  the  plant,  to  which  they  are 
more  or  less  similar  in  chemical  character.  The  above 
species  of  oak  is  very  plentiful  throughout  Asia  Minor 
from  the  Archipelago  to  the  confines  of  Persia,  and  from 
the  banks  of  the  Bosphorus  even  into  Syria.  It  seldom 
attains  a  greater  height  than  six  feet.  Its  stem  is 
crooked;  the  leaves  are  of  a  beautiful  green  color,  and 
the  acorn  is  two  to  three  times  larger  than  its  cup. 

The  cynips  is  a  small,  hymenopterous  insect,  with  a 
yellowish  body  and  brown  antennse.  It  pierces  the 
young  boughs  and  then  deposits  its  eggs.  This  prick  or 
wound  inflames  the  surrounding  vessels  and  causes  a 
swelling,  which  in  two  or  three  days  results  in  a  tumor- 


NUTGALLS, 


71 


like  excrescence  called  nutgalL  The  eggs  grow  with 
the  increase  of  the  galls,  and  maintain  the  inflammation 
until  the  young  are  hatched,  when  they  eat  their  way 
out  from  the  cavity  in  the  centre  of  the  nut.  The  most 
perfect  galls  are  those  harvested  before  the  larvae  have 
become  matured.  Those  collected  at  this  period,  ap- 
proach the  size  of  a  cherry,  and  are  known  in  commerce 
as  green,  blue,  or  black  galls,  while  those  gathered  later 
are  called  white  galls. 

The  gree7i  galls  have  a  dark  green  or  bluish  color, 
sometimes  inclining  to  brown;  are  hard,  compact,  and 
heavy,  with  pointed  excrescences  on  their  surfaces. 
Their  taste  is  very  astringent  and  bitter.  These  galls 
are  of  the  best  quality,  as  they  are  the  richest  in  tannin. 
They  are  brought  from  Aleppo,  Smyrna,  and  the  interior 
of  Asia  Minor. 

The  ivJiite  galls  have  a  brownish-yellow  color,  and  are 
larger  than  the  green  and  much  lighter,  owing  to  inju- 
ries received  from  the  insects.  They  are  also  less  bitter 
and  astringent,  and  contain  less  tannin,  and  are  there- 
fore inferior. 

French  galls,  produced  by  the  same  insect  upon  the 
oaks  of  that  country,  are  round,  smooth,  and  brownish, 
and  as  to  proportion  of  tannin,  rank  between  the  green 
and  white  galls. 

Chinese  galls,  are,  according  to  Decaisne,  a  product  of 
the  distylium  raeemosumygvowmg  in  Japan,  originating 
from  punctures  by  an  insect  allied  to  the  aphis.  They 
*  are  described  in  the  U.  S,  Dispensatory,  as  "  irregularly 
spindle-shaped  bodies,  often  more  or  less  bent,  with  ob- 
tusely pointed  protuberances  about  two  inches  long  by 
an  inch  in  diameter  at  the  central  thickest  part,  of  an 
ash  color,  and  soft  velvety  feel,  very  light,  hollow,  of  a 
slight  odor  resembling  that  of  ipecacuanha,  and  of  a 
bitter  astringent  taste." 


72 


NUTGALLS. 


According  to  Blej,  they  contain : — 


J.  dlllllll  •••••• 

69.00 

Eesin  and  fat  .... 

3.00 

Gallic  acid,  soluble  salts,  extractive 

and  albumen  .... 

4.00 

Starch   

7.35 

Lignin  ...... 

8.65 

Water  

8.00 

100.00 

The  eminently  astringent  property  of  galls,  and  their 
large  content  of  tannin,  render  their  use  very  service- 
able in  certain  operations,  of  which  we  shall  have  occa- 
sion to  speak. 

Aleppo  Gulls, — Guibourt's  analysis  of  Aleppo  galls 
shows  the  following  composition : — 


Water   11.5 

Woody  fibre   10.5 

Tannin   65.0 

Gallic  acid       .       .       .       .       .  2.0 

Ellagic  acid   2.0 

Brown  extractive     .       .       .       .  2.5 

Gum   2.5 

Starch   2.0 

Chlorophylle  and  vol.  oil  .       .       .  0.7 

Sugar   1.3 

Albumen  and  salts  ....  — 


100.0 

Galls,  therefore,  contain  sixty-five  per  cent,  of  tannin, 
while  the  oak  bark  collected  in  the  spring  gives  but 
0.6,  and  that  cut  in  the  autumn  only  0.45.  Braconnot, 
who  also  analyzed  galls,  obtained  30  of  gallic  acid,  and 


TREE  LEAVES. 


73 


an  insipid,  inodorous  constituent  in  white  powder,  and 
insoluble  in  boiling  water,  which  he  named  Ellagic  acid. 
According  to  this  chemist,  the  soluble  part  of  galls  con- 
sists of  gallic  and  ellagic  acids,  tannin,  and  oil.  Istrian 
galls,  according  to  Roder,  contain  only  twenty-four  per 
cent,  of  tannin. 

TREE  LEAVES. 

1.  The  leaves  of  the  different  species  of  willow  :  the 
salix  alba  (or  common  white  willow) ;  salixcaprea  (water 
willow) ;  salix  fragilis  (cracking  willow) ;  salix  pentan- 
dria  (red  willow) ;  salix  arenaria  (downy-mount  willow) ; 
salix  Bahylonica  (weeping  willow) ;  salix  aurigerana  ; 
salix  grandifolia;  salix  Pyrendica  (Pyrenean  willow); 
salix  nigricana  (black  willow) ;  salix  ccesia;  salix  lanceo- 
lata  (sharp-leaved  willow) ;  salix  vitellina  (yellow  wil- 
low); salix  incana;  saZicc  mmmaZzs  (Osier  willow). 

2.  The  leaves  of  the  sorbus  domestica  (service-tree);  and 
of  the  sorbus  aucuparia  (mountain  ash). 

3.  Of  the  pomegranate,  or  punica  granatum. 

4.  Of  the  fagus  sylvatica,  or  beech-tree;  and  of  the 
fagus  castanea  (chestnut-tree). 

5.  Of  the  olea  Europa^  (olive-tree). 

6.  Of  the  mespilus  Germanica  (common  medlar);  and 
mespilus  cotoneaster, 

7.  Of  the  cornus  mas,  and  cornus  sanguinea  (common 
dogwood) . 

8.  Of  the  corylus  avellana  (hazel-nut-tree) . 

9.  Of  the  betula  alnus,  and  betula  alba  (common  birch). 

10.  Of  the  Tosa  gallica  (red  rose),  and  rosa  semper  vi- 
reus  (evergreen  rose),  and  others. 

11.  0^  the  riibus  fruticosus  (common  bramble);  rubiis 
cousins  (dewberry);  and  probably  also  of  the  rubus  idceiis 

6 


74 


TREE  LEAVES. 


(raspberry).  The  cloudberry  [ruhus  chamcemorus)  con- 
tainSj  according  to  Wolfgang,  7.3  per  cent,  of  tannin. 

12.  Of  the  Titmex  aguaticus  (yellow-rooted  water  dock) . 

13.  Of  the  Tosmariims  officinalis  (rosemary). 

14.  Of  the  qiierciis  robur  (common  European  oak) ; 
quercus  cerris  (Turkey  oak);  quercus  sessiflora  (sessile- 
flowered  oak);  quercus  toza  (hoary  oak);  quercus  Apen- 
nina  (Apennine  oak);  and  quercus  ilex  (evergreen  oak). 

The  leaves  of  the  quercus  robur  contain  the  most  tan- 
nin. 

15.  Of  nearly  all  of  the  Cistus  family,  especially  of  the 
cistus  ledon,  or  Monspeliensis  (Montpelier  rock-rose);  cistus 
albiclus  (white-leaved  rock-rose);  cistus  incanus  Ion gifolius 
(hoary  rock-rose) ;  cistxis  populifolius^  &c,  (poplar-leaved 
rock-rose) . 

16.  Of  the  erica  vulgaris  (common  heath);  erica  cinerea 
(fine-leaved  heath) ;  erica  scoparia;  erica  tetralix  (cross- 
leaved  heath);  erica  purpurescens.  According  to  Tournal, 
the  leaves  of  the  heath  have  not  half  the  tanning  power 
of  oak  bark,  and  this  fact  is  confirmed  by  the  abandon- 
ment of  their  use  in  England,  where  they  were  once 
largely  employed.  Oak  barks,  from  the  North  of  Europe, 
and  especially  from  Belgium,  though  of  inferior  quality, 
are  now  substituted  for  them. 

17.  Of  the  tamarix  Gallica  (French  tamarisk) ;  and  tama- 
rix  Africana  and  Germanica  (African  and  German  tama- 
risk) . 

18.  Of  the  cynara  scolymus  (garden  artichoke).  It  is 
recorded  [Bibliotlieque  Physico-Economique,  vol.  i.  1789) 
that  goat  and  calf  skins,  for  bookbinders'  use,  have  been 
tanned,  in  England,  in  a  decoction  of  artichoke,  as  well  as 
they  could  be  done  by  nutgalls  or  willow  bark.  The 
twigs  and  leaves  of  the  cynara  cardunculus  (cardom.) 
are  equally  eflBcient. 


TREE  LEAVES. 


75 


19.  Of  the  prunus  spinosa  (sloe-tree).  Calfskins  have 
been  tanned  in  London  with  the  leaves  of  this  tree  boiled 
in  a  decoction  of  barley.  It  is  probable  that  small  pro- 
portions of  tannin  are  contained  in  the  prunus  domestica 
(common  plum);  primus  Brigantiaca  (Briancon  apricot); 
prunus  Armeniaca  (common  apricot) ;  in  the  amygdalus 
communis  (sweet  almond) ;  amygdalus  Persica  (common 
peach) ;  and  in  the  primus  cerasus^  or  common  cherry, 
and  other  kinds  of  cherry. 

20.  Of  the  conmw2  wac2^toi«m  (spotted  hemlock) .  The 
tanning  principle  is  prepared  by  macerating  the  powdered 
bark  and  shoots  in  cold  water,  and  then  boiling  in  a  cop- 
per kettle.  The  bark  is  reboiled  with  fresh  waters  until 
exhausted,  and  the  several  liquors  are  then  united  and 
evaporated  to  a  proper  consistence. 

Schroeder  analyzed  the  fresh  leaves,  but  as  his  result 
does  not  show  the  presence  of  tannin,  it  must  either  be 
incorrect  or  else  there  are  other  tanning  principles. 

An  infusion  of  the  artemisia  absinthium  (wormwood) 
precipitates  gelatine  in  brown  flakes,  though  Braconnot 
does  not  give  tannin  in  his  analysis  as  one  of  its  con- 
stituents. 

An  infusion  of  the  gentiana  centaureum  also  precipi- 
tates gelatine  in  straw-colored  flakes. 

21.  Of  the  wscidits  Jiippocastanum  (horse-chestnut). 
The  hulls,  as  well  as  the  young  fruit,  also  contain  tan- 
nin. 

22.  Of  the  geranium  pratense  (crowfoot-leaved  cranes- 
bill). 

23.  Of  the  Oenothera  hiennis  (common  Oenothera  or 
evening  primrose). 

24.  Of  the  tilia  Europcea  (lime-tree). 

25.  Of  the  arbutus  uva  ursi  (bear-berry). 

This  evergreen  shrub  is  indigenous  to  the  mountain 


76 


TEA. 


regions  of  Catalonia^  Italy,  and  the  South  of  France,  but 
grows  abundantly  in  this  country,  in  New  Jersey  and 
in  the  northern  States.  It  has  a  trailing,  round,  and 
reddish  stem,  and  thick,  oval,  shining  leaves,  of  a  deep 
green  color  on  the  upper,  and  pale  green  on  the  lower 
side.  They  are  slightly  odorous,  and  very  astringent. 
The  flowers  cluster  at  the  ends  of  the  branches,  and  have 
red  calyces  and  white  corollas  with  red  lips.  The  fruit 
is  a  small,  round,  red  berry,  containing  five  seeds,  and  has 
a  tart,  acidulous  taste.  The  market  in  this  vicinity  de- 
rives its  supply  of  leaves  mostly  from  New  J ersey.  The 
imported  article  is  frequently  adulterated  with  the  leaves 
of  the  cow-berry  (yaccinum  vitis  idceae).  The  genuine 
leaves  are  of  a  beautiful  green  color,  thick,  oval,  and  less 
round  than  the  fraudulent  ones,  which  are  dotted  instead 
of  being  reticulated  on  the  under  surface.  The  genuine 
leaves  have  a  strong  odor  and  astringent  taste,  and  give, 
by  triturition  with  distilled  water,  a  cloudy,  yellowish 
liquor,  which,  by  filtration  through  sulphate  of  iron,  pro- 
duces a  blue  precipitate,  and  becomes  almost  discolored. 
This  reaction  is  due  to  the  presence  of  tannin,  the  large 
proportion  of  which  renders  the  leaves  available  for  tan- 
ning, - 

TEA. 

The  tea  plant,  tJiea  Cliinensis,  is  an  evergreen  shrub, 
indigenous  to  China  and  Japan,  in  both  of  which  coun- 
tries it  is  largely  cultivated.  It  has  also  been  grown 
with  success  in  South  Carolina,  and  may  yet  become  one 
of  the  agricultural  products  of  that  State. 

There  are  several  commercial  varieties  of  tea :  the  Hy- 
son, Gunpowder,  Imperial,  Scliulong,  and  Bohea,  classified 


TEA. 


77 


under  the  designations  of  green  and  hlach  teas;  but  War- 
rington's investigations  (Chemist^  1851)  have  well  esta- 
blished the  fact  that  the  green  and  black  teas  are  from 
the  same  plant,  and  this  strengthens  the  belief  that  there 
is  but  one  species  of  tea  plant.  Thea  stricta,  T.  BoJiea^ 
and  T.  viridis,  are  consequently  not  different  species,  but 
identical. 

The  color,  flavor,  form,  and  strength  of  the  different 
kinds  of  tea  in  commerce,  vary  with  the  preparation  and 
mode  of  manipulating.  The  leaves  for  green  teas,  are 
transferred  to  the  roasting  or  drying  pan  as  soon  as  har- 
vested, and  are  at  once  highly  heated  during  stirring;  but 
those  for  hlack  teas  are  left  in  heaps  for  some  time,  where 
by  spontaneous  heating  they  undergo  a  kind  of  slow  fer- 
mentation, which  changes  the  nature  of  their  constituents 
and  consequently  their  flavor.  The  leaves  thus  heated, 
as  soon  as  they  have  withered  and  acquired  a  certain 
degree  of  fragrance,  are  removed  to  the  roasting-pan. 
The  black  color  is  due  to  the  oxidation  of  the  extractive 
of  the  leaves,  and  not  to  artificial  coloring  matter,  which 
is  probably  the  same  for  both  kinds  of  tea,  and  consists 
of  a  mixture  of  Prussian  blue,  gypsum,  and  turmeric. 
This  coloring  matter  is  called  the  glazing,  and  tea  glazed 
to  the  maximum,  is  that  variety  known  as  gunpowder. 
Schulong  tea  is  the  hyson  aromatized  with  the  leaves 
of  the  olea  fragrans  (fragrant  olive).  The  manner  of 
rolling,  and  possibly  the  age  of  the  leaves  at  the  time  of 
harvesting,  constitute  the  difference  in  other  varieties. 

The  composition  of  tea  is  shown  by  G.  J.  Mulder's 
analyses  {Ann.  der  Pharm.  xxviii.),  as  follows: — 


78 


FLOWEES  AND  FLOWER  TOPS. 


Green. 

Black. 

Volatile  oil 

.  0.79 

0.60 

Clilorophylle 

.  2.22 

1.84 

Wax  .... 

.  0.28 

Resin 

.  2.22 

3.60 

Gum  .... 

.  8.56 

7.28 

Tannin  (as  in  galls) 

.  17.80 

12.88 

Thein 

.  0.43 

0.46 

Extractive  . 

.  22.80 

19.88 

Apotheme  . 

.  traces 

1.48 

Muriatic  extract . 

2o.o0 

19. 

AlliiiTnPTi 

3.00 

2.80 

Lignin 

.  17.68 

28.32 

Salts  .... 

.  5.56 

5.24 

104.94 

103.50 

Franck  obtained  34.6  tannin  from  green,  and  40.6 
from  black  tea.  Rochelder  found  hoJieic  acid,  also,  in 
the  latter.  The  amount  of  thein,  according  to  Peligot, 
is  from  2.5  to  4  per  cent.  The  tannin  of  tea  is  similar 
in  properties  to  quercitannin. 

FLOWERS  AND  FLOWER  TOPS. 

1.  Of  the  poi^e/i^^7Za  a725m72a  (wild  tansy) . 

2.  Of  the  agrimonia  eupatoria  (agrimony). 

3.  Of  the  eugenia  caryojphillata  (clove-tree),  which, 
according  to  Tromsdorff,  contains  .13  of  a  peculiar 
tannin. 

4.  polygonum  historta  (snake's  weed). 

5.  Of  the  geum  urbanum  (common  avens).  This  is  a 
perennial  European  plant,  which  grows  wild  in  damp 
and  shady  places.  The  root  is  a  quarter  of  an  inch 
thick,  more  or  less;  white  interiorly,  reddish  exteriorly 


FLOWERS  AND  FLOWER  TOPS. 


79 


and  at  the  centre,  and  has  long  descending  fibres.  The  odor 
of  the  dry  root  assimilates  to  that  of  cloves,  and  its  taste 
is  astringent  and  slightly  bitter.  The  proper  time  for 
gathering  it  is  the  spring,  and  the  heat  by  which  it  is 
dried  should  be  low  and  cautiously  managed. 

TromsdorfF's  analysis  of  the  root  shows  that  it  is  rich 


in  tannin. 

Volatile  oil  (heavier  than  water)     .  0.39 

Kesin   40.00 

Tannin  (soluble  in  alcohol  and  ether, 

and  blues  iron  salts)    .       .       .  410.00 

Adragan  thine        .       .       .       .  92.00 

Gummy  niatter      ....  158.00 

Woody  fibre   300.00 


1000.39 

The  water  avens  [geuni  rivale),  which  grows  in  Europe 
and  in  this  country  from  Canada  to  Pennsylvania,  as 
well  as  that  from  the  Pyrenees  {geum  Pyrendicum)  ^ 
likewise  possess  tanning  properties. 

6.  Of  the  filix  mas  (male  fern).  The  other  species  of 
fern  may  also  be  used  in  tanning. 

7.  Of  the  fragaria  vesca  (wood  strawberry). 

8.  Of  the  spircea  filipendula  (drop wort). 

9.  Of  the  Jiypericum 'perforatum  (St.  John's  wort). 

10.  Of  the  filago  Oermanica  (common  cotton  rose). 

11.  Of  the  vinca,  major  and  minor  (greater  and  lesser 
periwinkle) . 

12.  0^  the  j)oIygonum  persicaria  (spotted  persicaria). 

13.  0^  the  plantago  7najor  (plantain). 

14.  Of  the  alcfiemilla  vidgaris  (ladies  mantle). 

15.  Of  the  grapJialium  diaicum  (everlasting). 

16.  the  equisetum palustre  (marsh  horse-tail). 


80 


FRUITS — SEEDS  AND  BULBS. 


17.  Of  the  potei^um  sanguisorba  (common  burnet). 

18.  Of  the  lichen pulmonarius  (lungwort). 

19.  Of  the  potentilla  reptans  (cinquefoil) ;  potentilla 
canilescens  (Alpine  cinquefoil) ;  and  potentilla  palustre 
(marsh  cinquefoil). 

20.  Of  the  spircea  ulmaria  (meadow-sweet). 

21.  Of  the  tormentilla  erecta  and  reptans  (common  and 
large-flowered  septfoil) . 

22.  Of  the  geranium  grandifioTum ;  g.  sylvaticum  (wood 
cranesbill) ;  and  g.  pratense  (crowfoot-leaved  cranesbill). 

23.  Of  the  humulus  lupulus  (hop  plant).  Lupulin,  a 
yellowish  powder,  which  is  separated  from  the  fruit  or 
strobiles  by  rubbing  and  sifting,  contains,  according  to 
Ives,  more  than  0.4  of  tannin  and  gallic  acid. 

24.  Of  the  rosa  GalUca  (red  rose).  The  infusion  of 
properly  dried  rose-leaves  reddens  litmus;  precipitates 
gelatine,  sulphate  of  iron,  nitrate  of  bismuth,  and  oxalate 
of  ammonia,  thereby  proving,  by  these  reactions,  the 
presence  of  an  acid,  a  lime  salt,  tannin,  &c. 

FRUITS  SUITABLE  FOR  TANNING. 

1.  The  nuts  of  the  common  cypress  [cupressus  semper 
virens). 

2.  The  marc  of  grapes  {vitis  vinifera),  * 

3.  The  outer  shell  of  the  butternut  [juglans  regia), 

4.  Star  aniseed  or  badiane  of  the  French  {illicium 
anisahim),  which  contains,  according  to  Meisner,  3.2  per 
cent,  of  tannin. 

SEEDS  AND  BULBS  SUITABLE  FOR  TANNING. 

1.  Those  of  the  grape  contain  much  tannin,  and  give 
very  good  results. 


SEEDS  AND  BULBS. 


81 


2.  Of  the  liydro-sapathum  and  loild  cornel. 

3.  Attempts  have  frequently  been .  made  to  use  the 
dividivi,  or  leby-diby,  the  hulls  of  the  fruit  of  the  ccesal- 
"pina  coriaria,  a  tree  growing  in  Carthagena  and  Mexico. 
They  contain  a  considerable  quantity  of  tannin.  The 
pods  are  dry  and  curled,  about  three  inches  long,  and  of 
a  dark-brown  color.  The  tannin  of  this  substance,  which 
exists  wholly  in  the  rind  beneath  the  epidermis,  gives 
no  gallic  acid  upon  dry  distillation,  but  produces  the 
same  color  with  persalts  of  iron  as  gall-tannin.  The  ob- 
jectionable brown  color  imparted  to  leather  made  with 
this  material,  may  be  prevented  by  keeping  the  infusion 
out  of  contact  with  the  air  during  the  process  of  tanning. 
This  color  is  thought  to  be  produced  by  the  fermentation 
of  the  infusion. 

4.  The  bulb  of  the  scuilla  maritima,  a  perennial  plant, 
indigenous  to  Barbary,  Sicily,  and  Spain.  There  are 
two  varieties  of  squill,  the  red  and  white  bulb ;  but  they 
do  not  differ  in  properties.  Before  being  sent  to  market, 
they  are  thinly  sliced  and  dried.  During  this  desicca- 
tion, the  loss  of  weight  amounts  to  82  in  every  100  parts. 

Squill  has  a  bitter,  nauseous,  acrid  taste ;  and  when 
applied  to  the  skin  causes  it  to  inflame.  It  partially 
loses  its  acrimony  by  drying.  The  viscid  juice  which 
it  contains  reddens  syrup  of  violets.  Squill  yields  its 
active  principles  to  water,  alcohol,  and  vinegar.  Yogel 
found  in  one  hundred  parts  of  dry  squill, 

Gum 

Bitter  principle  {scillitin) 
Tannin 

Saccharine  matter 
Woody  fibre 

100 


35 
24 
6 
29 


82 


WOODS  AND  ROOTS. 


According  to  Duncan  and  Buchner,  the  presence  of 
tannin,  in  any  considerable  quantity,  is  doubtful. 

5.  Yalonia, — This  material  comes  from  Smyrna  and 
the  Morea.  It  consists  of  the  dried  acorn  hulls  of  the 
prickly-cupped  oak  [quercus  cegilops).  There  are  two 
varieties,  the  common  and  the  camata.  The  latter  is  of 
the  size  of  a  cherry,  and  is  the  richest  in  tannin.  The 
diameter  of  the  common  is  nearly  two  inches. 

The  leather  made  with  valonia  is  said  to  be  firmer 
and  heavier  than  the  oak-tanned.  When  mixed  with 
oak  bark,  it  forms  a  very  economical  and  advantageous 
material.  Two  pounds  of  valonia  are  required  to  make 
one  pound  of  leather. 

WOODS  SUITABLE  FOR  TANNING. 

The  wood  of  almost  every  tree,  the  bark  of  which  is 
rich  in  tannin,  also  contains  it.  Among  others,  we  will 
name  the  different  species  of  oak,  the  horse-chestnut, 
service-tree,  and  Pernambuco  or  Brazilletto. 

ROOTS  SUITABLE  FOR  TANNING. 

1.  The  dentellaria,  or  lead  wort  [plumbago  Europcea), 
a  perennial  herbaceous  plant,  growing  wild  in  the  south 
of  France,  contains,  according  to  Tournal,  a  considerable 
quantity  of  tannin. 

2.  The  male  fern  (aspidium  filix  mas),  growing  abund- 
antly in  moist  and  shady  places  throughout  Europe.  Its 
root,  when  dry,  is  externally  brown  and  yellowish-white 
or  reddish  within.  According  to  Morin  and  Peschier,  it 
is  composed  of  volatile  and  fat  oils,  gallic,  and  acetic 
acids,  tannin,  starch,  resinous  and  coloring  matters, 
woody  fibre,  &c. 


ROOTS. 


83 


3.  Khatany  (Jcrameria  triandria).  A  shrub,  indigen- 
ous to  Peru,  growing  in  mountainous  districts,  and  flow- 
ering at  all  seasons.  As  found  in  commerce,  it  is  in 
pieces  of  irregular  shapes  and  size,  sometimes  not  thicker 
than  a  pipe-stem,  and  at  others  an  inch  in  diameter,  and 
two  or  three  feet  in  length.  Occasionally,  several  of  the 
stems  issue  from  one  head.  The  bark  is  of  a  dark  yel- 
low or  brown  color,  readily  separable  from  the  wood,  and 
has  an  astringent,  nauseous,  and  slightly  bitter  taste. 
The  woody  part  has  less  taste,  and  a  color  more  ap- 
proaching to  red.  Boiling  water  extracts  its  virtues,  and 
this  decoction,  which  has  a  deep  brown  color,  is  abund- 
antly precipitated  by  the  mineral  acids.  The  alkalies 
only  change  its  color  to  that  of  urine.  Sulphate  of  iron 
produces  a  black,  and  acids  a  fawn-colored  precipitate. 
Gelatine  proves  the  presence  of  tannin.  From  the  ana- 
lyses of  various  chemists,  we  find  that  it  is  composed  of 
tannin,  woody  fibre,  gum,  starch,  saccharine  matter,  and 
krameric  acid.  One  portion  of  the  tannin  has  lost  its 
astringency  and  been  rendered  insoluble  by  the  action  of 
the  air ;  another  portion  exists  as  soluble  extractive,  and 
the  remainder  is  normal. 


Composition  of  Khatany  Root. 

C.  G-.  G-melin.  Peschier. 

Tannin  . 
Gallic  acid 
Sweet  matter  . 
Nitrogenous  matter 
Mucilage 
Lignin 

Krameric  acid 
Gum,  extractive  and  color- 


38.3  42.6 

—  0.3 
6.7  — 
2.5  — 
8.3  — 

43.3  — 

—  0.4 


ing  matter  ...         —  56.7 


99.1 


100.0 


84  BARKS.  V 

4.  Leopard^ s  hane  {arnica  montana). — Ffaff  obtained 
from  the  root  of  this  plant  thirty-two  per  cent,  of  ex- 
tractive matter  analogous  to  tannin,  and  which  gave  a 
green  precipitate  with  the  salts  of  iron. 

5.  Statice,  or  Marsh  Rosemary. — The  Kalmucs  use  a 
decoction  of  statice  and  sour  milk  for  tanning  goat  and 
sheep  skins  as  materials  for  clothing.  Tournal  has  drawn 
attention  to  this  plant  as  a  substitute  for  oak  bark,  in 
localities  where  that  substance  is  not  abundant.  Of  the 
several  species,  the  statice  limonium  contains  the  most 
tannin.  Parrish  found  in  the  statice  Caroliniana  12 A 
per  cent,  of  tannin. 

BARKS. 

The  bark  is  that  portion  of  the  plant  which  envelops 
the  root,  trunk,  and  branches,  and  may  be  compared  to 
the  integument  of  an  animal;  like  it,  protecting  the  deli- 
cate organs  within  from  external  injurious  impressions, 
and  subserving  other  and  somewhat  similar  purposes.  It 
consists  of  four  distinct  layers,  the  epidermis,  the  cellular 
integument,  the  cortex,  and  the  liher. 

The  epidermis  is  the  thin,  dry,  transparent,  non-elastic 
membrane  forming  the  outer  covering  of  the  bark,  and 
presenting  a  striking  analogy  to  the  cuticle  of  animal 
skins.  As  the  plant  grows  old,  this  coating  thickens  by 
the  superposition  of  internal  layers,  and  eventually 
cracks — becomes  detached,  and  falls  off.  The  vital  prin- 
ciple seems  wanting  in  the  epidermis,  and  it  seldom  or 
never  contains  astringent  or  other  substances. 

The  cellular  integument,  or  parenchyma,  is  the  greenish, 
succulent  layer,  immediately  under  the  epidermis.  It  is 
generally  the  seat  of  color,  being  thus  analogous  to  the 
rete-mucosum  of  animals.    The  stems  and  branches  of 


BARKS. 


85 


both  annual  and  perennial  plants  are  invested  with  it; 
but  in  woody  plants  it  is  dried  up  and  reproduced  con- 
tinually. The  old  layers  remain — are  pushed  outwards 
by  the  new  ones,  and  form,  at  length,  the  rigid,  dry,  dead 
covering  of  the  old  trunks  of  trees. 

The  cortex  J  or  true  harh,  consists  of  but  one  layer  in 
plants  and  branches  only  a  year  old;  but  in  the  older 
branches  and  trunks  of  trees,  it  consists  of  as  many 
layers  as  they  have  years  of  age.  The  bark  contains  a 
large  number  of  woody  fibres  running  generally  in  a 
longitudinal  direction.  These  give  it  tenacity,  and  when 
separated  by  maceration,  usually  exhibit  a  network  of 
a  regularly  reticulated  structure.  The  virtues  or  pro- 
perties of  particular  plants  reside  chiefly  in  this  bark, 
and  principally  in  its  inner  layers.  This  is  the  case 
with  certain  resins  and  aromatic  oils,  with  the  bitter  of 
cinchona,  and  the  tannin  of  the  oak  and  willow. 

The  liber  is  the  inner  layer  of  the  cortex,  and  con- 
sists of  laminaB,  bound  together  by  a  cellular  matter, 
which  when  dissolved  by  maceration  in  water,  detaches 
these  plates  from  each  other.  The  most  essential  vital 
functions  are  carried  on  in  this  layer,  and  its  destruction 
is  generally  fatal  to  the  life  of  the  plant,  while  the  outer 
bark  may  be  peeled  off  without  injury  to  it.  Advantage 
of  this  fact  is  taken  in  girdling  trees,  an  operation  which 
is  not  successful  unless  the  axe  is  made  to  penetrate 
below  the  liber. 

Cinnamo7i. — This  is  the  bark  of  the  laurus  cinnamo- 
murn,  from  which  the  epidermis  or  cuticle  has  been  re- 
moved by  scraping.  The  tree  is  indigenous  to,  and 
abounds  in  the  island  of  Ceylon;  and  grows  also  in  Co- 
chin-China,  Sumatra,  the  Cape  de  Yerds,  Isle  of  France, 
Brazil,  Cayenne,  and  some  of  the  West  India  Islands. 


86 


BARKS. 


Of  the  many  varieties^  the  following  are  the  most  im- 
portant : — 

1.  Cinnamon  of  Ceylon, — This  is  found  in  commerce 
in  thin,  quill-shaped  pieces,  the  smaller  of  which  are  in- 
closed in  the  larger,  so  as  to  form  concentric  cylinders. 
These  quills  are  met  with  in  bundles  tied  together  with 
bamboo  string.  It  is  of  a  light-brown  yellow  color,  of  a 
peculiar  agreeable  odor,  and  aromatic,  pungent,  sweetish 
taste.  It  is  very  brittle  and  friable.  This  is  the  most 
costly  variety,  and  it  owes  its  flavor  to  a  volatile  oil. 

2.  Cinnamon  of  China.  —  This  variety,  though  of 
very  good  quality,  is  inferior  to  the  preceding.  The 
bark  is  heavier,  thicker,  of  a  deeper  color,  and  of 
stronger  but  less  agreeable  taste.  It  is  known  in  com- 
merce as  cassia,  and  comes  in  single  quills. 

3.  Cayenne  Cinnamon. — Of  this  there  are  two  sub- 
varieties.  The  first  is  that  from  trees  of  Ceylon  stock. 
It  is  paler  and  thicker  than  that  from  Ceylon,  owing,  as 
Guillemin  says,  to  the  too  great  age  of  the  branches 
from  which  it  is  taken.  The  second  is  the  product  of 
a  cinnamon-tree  introduced  from  Sumatra,  and  is  very 
similar  to  that  from  China.  It  is  thick,  of  a  very  strong 
taste  and  smell,  and  very  mucilaginous. 

Birch  Bark. — This  is  the  bark  of  the  hetula  alnus,  a 
tree  which  abounds  in  the  dry,  barren  portions  of  the 
Middle  States,  and  grows  to  a  great  height.  The  epi- 
dermis consists  of  thin,  white  layers,  which  in  ancient 
times  served  as  a  substitute  for  writing-paper.  The 
inner  bark  is  astringent,  and  is  used  for  tanning  "  Rus- 
sia" leather.  According  to  Davy,  it  contains  6.75  per 
cent,  of  tannin.  Distillation  hy  descent  yields  a  fragrant 
brown  oil,  to  which  the  Russia  leather  owes  its  odor  and 
durability. 

Chestnut  Barh. — We  have  already  mentioned  the  chest- 


BARKS. 


87 


nut-tree.  The  American  species  [castanea  vesca)  grows 
in  gravelly  or  sandy  soils,  and  yields  a  bark  wliich  con- 
tains upwards  of  4.0  tannin.  Leather  tanned  with  it 
is  said  to  possess  greater  solidity  and  flexibility  than  that 
made  with  oak  bark. 

Hoi'se-cJiestnut. — This  tree  is  the  cesculus  Mppocastanum, 
indigenous  to  America,  but  cultivated  in  Europe.  It  con- 
tains, according  to  Davy,  1.875  per  cent,  of  the  kind  of 
tannin  which  colors  the  salts  of  iron  green.  The  Ame- 
rican variety  is  known  as  OJiio  hucheye. 

Sassafras. — The  bark  of  the  root  of  the  laurus  sassa- 
fras consists,  according  to  Reinsch,  of 


Water  

90 

Essential  oil       ....  . 

8 

Fatty  matter  ..... 

8 

Balsamic  resin  and  wax 

50 

Sassafride  1  extracted  by     .       .  . 

92 

Tannin     J  strong  alcohol  . 

58 

Sassafride, 

Tannin,     >  extracted  by  weak  alcohol 

68 

and  Gum  j 

Soluble  albumen  ..... 

6 

Gum,  coloring  matter,  and  salts  . 

30 

Fecula,  tannin,  &c.  (extracted  by  boiling 

water)  

54 

Fecula,  tannin,  &c.,  dissolved  out  by 

caustic  potassa  lye  .... 

289 

Lignin  ...... 

247 

1000 

Larch  Barh. — The  larch-tree,  known  also  as  cedar  of 
Lebanon^  is  a  beautiful  tree,  much  valued  for  its  timber. 
There  are  three  varieties:  the  ahies  larix,  or  common 


88 


BARKS. 


white  larch,  indigenous  to  Germany;  the  black  (L.  pen- 
dula)y  and  the  red  (Z.  microcarpa),  natives  of  North 
America,  but  all  largely  cultivated  in  the  mountainous 
parts  of  Scotland.  Its  bark  contains  nearly  two  per 
cent,  of  tannin.  It  is  mostly  used  for  tanning  hasils,  an 
inferior  quality  of  sheepskins. 

The  American  larch,  or  so-called  Jiackmatach  or  tama-  • 
rach^  is  doubtless  one  of  the  above  varieties.  It  abounds 
in  Newfoundland,  near  the  St.  Lawrence,  and  as  far 
south  in  the  United  States  as  the  northern  part  of  Penn- 
sylvania. The  bark  of  the  trunk  is  smooth,  but  rugged 
on  the  smaller  branches. 

Hemlock  Spruce,  or  Abies  Canadensis. — This  tree  is 
natural  to  the  coldest  regions  of  America,  and  consti- 
tutes three-fourths  of  the  evergreen  woods  in  Nova 
Scotia,  New  Brunswick,  Maine,  Vermont,  and  part  of 
New  Hampshire.  It  is  less  common  further  south ;  but 
is  found  in  the  middle  and  southern  States  on  the  Alle- 
ghanies.  It  grows  to  a  height  of  70  to  80  feet,  with  a 
uniform  circumference,  for  two-thirds  of  its  length,  of  6 
or  9  feet.  The  bark  is  of  a  gray  color  when  young,  but 
grows  lighter  when  old,  and  is  generally  covered  with 
moss.  The  leaves  are  6  or  8  lines  long,  flat,  irregularly 
disposed  in  two  ranks,  and  downy  at  their  unfolding. 
Its  flowers,  which  appear  in  May,  are  preceded  by  cones 
of  a  dark  ash  color.  The  bark  is  largely  used  in  this 
country  as  a  substitute  for  that  of  the  oaks  in  tanning. 
It  is  taken  from  the  tree  in  June,  and  half  of  the  epi- 
dermis is  shaved  ofi"  before  it  is  ground.  It  imparts  its 
red  color  to  leather  made  with  it,  which  is  said  to  be  in- 
ferior to  that  made  with  oak  bark;  but  the  two  kinds 
united  are  supposed  to  produce  better  leather  than 
either  of  them  alone. 

Hazel  Bark. — The  product  of  the  corylus  avellana,  a 


BARKS. 


89 


bushy  tree,  growing  wild  in  Europe,  and  in  our  middle 
States,  and  in  some  countries  cultivated  extensively  for 
its  fruit,  which  is  the  filbert,  or  stochiut  Davy  obtained 
2.916  of  tannin  from  it. 

Beech  Barh. — From  the  fagus  sylvatwa,  a  beautiful 
forest-tree,  indigenous  to  the  North  of  Europe  and  North 
America.  It  grows  throughout  the  United  States,  and 
is  very  abundant  in  Pennsylvania,  New  York,  Kentucky, 
and  Tennessee.  It  is  classified  into  two  varieties,  which 
take  their  names  from  the  color  of  the  wood :  the  white, 
or  fagus  sylvestris  ;  and  the  red,  or  fagus  ferruginea.  The 
latter  is  very  rare  in  the  western  or  southern  States. 
Beech  bark  is  of  a  silvery  color,  and  contains  nearly  3 
per  cent,  of  tannin.  In  some  localities,  where  oak  is 
scarce,  the  white  beech  bark  is  used  for  tanning  pur- 
poses, and  makes  a  white  but  inferior  leather. 

Lomhardy  Poplar  Barh. — From  the  populus  fastigiata. 
It  contains  3.12  of  tannin,  and  makes  a  lighter-colored 
leather  than  oak  bark,  imparting,  at  the  same  time,  a  fra- 
grant odor  similar  to  that  of  Russia  leather. 

Blach  Thorn  Barh. — This  is  from  the  sloe-tree  (prunus 
spinosa)  or  wild  plum-tree,  and  contains  3.32  of  tannin. 
The  black  thorn  of  the  United  States  is  the  yellow  cratce^ 
gus  of  botanists. 

Pomegranate  Barh, — The  pomegranate  {pimica  graria- 
turn)  is  a  shrubby  tree  of  African  origin ;  but  growing 
wild  in  Spain,  Italy,,  and  the  West  Indies.  It  is  also 
cultivated  in  our  southern  States.  There  are  two  varie- 
ties, distinguished  by  the  taste  of  their  fruit,  which  is 
sour  from  one,  and  sweet  from  the  other.  The  rind  of 
the  fruit,  the  flowers  and  bark  of  the  root,  each  and  all 
abound  in  tannin.  The  rind  of  the  fruit,  as  found  in 
commerce,  is  reddish-brown,  hard,  dry,  and  of  a  sharp 
astringent  taste.  The  bark  of  the  roots,  which  are  com- 
7 


90 


BARKS. 


pact  and  knotty,  is  thin,  of  a  brownisli-yellow  color,  and 
of  a  short,  brittle  fracture.  It  comes  in  quills,  is  very 
astringent,  and,  when  chewed,  colors  the  saliva  yellow. 

Ash  Baric. — The  tree  [fraxinus  exce?<s?'or),  bearing  this 
bark,  abounds  in  our  forests,  and  grows  to  a  great  height. 
Both  the  leaves  and  bark  have  a  very  bitter  astringent 
taste.  The  bark  contains,  according  to  Davy,  3.3238 
per  cent,  of  tannin. 

Elm  Barh. — The  elm  (idmus  campestris),  cultivated 
in  the  United  States  as  an  ornamental  tree,  yields  a 
rough,  iron-gray  colored  bark,  of  a  sharp  bitter  taste, 
which  contains,  according  to  Davy,  2.706  per  cent,  of 
tannin.  Some  of  the  varieties  of  the  elm  exist  in  parts 
of  the  United  States  as  forest- trees. 

Cinchona  Barh, — The  cinchona  is  a  South  American 
tree,  of  which  Guibourt  has  described  twenty-five  species, 
and  the  number  is  further  increased  by  the  additions  of 
other  naturalists.  We  shall  confine  our  notice  to  those 
more  particularly  containing  the  tanning  principle. 

The  most  valuable  kinds  of  bark  come  from  the  Pa- 
cific coast  of  South  America,  and  are  classified  in  com- 
merce, according  to  their  color,  into  ^aZe,  yellow^  and  red 
barks,  all  of  which  contain  tannin. 

The  j^ale  harh,  called  by  the  French  gray  bark,  from  the 
color  of  the  epidermis,  reaches  market  in  single  or  dou- 
ble quills.  Its  taste  is  somewhat  astringent.  This  bark 
is  derived  from  the  cmchona  Cmdaminea.  The  yellow 
harhy  in  quills  or  flat  pieces,  is  from  the  cinchona  calisaya. 
Red  harky  called,  in  South  America,  cascarilla  roxa  and 
color ada,  comes  also  in  quills  or  flat  pieces,  but  the  spe- 
cies of  cinchona  which  bears  it  is  unknown.  The  Car- 
thagena  barks,  an  inferior  species  of  cinchona,  also 
contain  tannin. 

All  of  the  foregoing  possess  highly  medicinal  proper- 


BARKS. 


91 


ties,  and,  on  that  account,  are  too  valuable  to  be  used  as 
tanning  material  in  this  country. 

Corlc-tree  Barh, — The  inner  bark  of  the  querciis  liher, 
or  cork  oak,  a  tree  indigenous  to,  and  abundant  in  Corsica 
and  Spain.  The  tannin  which  it  contains  is  similar  to 
that  from  catechu,  and  imparts  to  the  leather  an  objec- 
tionable dark  color.  It  has  twice  the  tanning  power  of 
oak  bark,  and  is  largely  used  for  the  purpose  in  Ireland 
and  England. 

Poison  OaJc, — The  poison  oak  is  the  rJius  toxicoden- 
dron and  rJms  radicans  of  Linnasus.  The  two  were  for- 
merly considered  distinct  varieties,  but  they  are  only 
different  stages  of  the  same  growth,  radicans  being  ap- 
jDlied  to  the  creeping  parasite,  and  toxicodendron  to  the 
early  vine.  It  grows  wild  throughout  the  United  States, 
and  bears  small,  greenish- white  flowers  in  J une  and  July. 
This  plant  contains  tannin,  gallic  acid,  resin,  &c.,  and 
evolves  a  volatile  principle,  which  is  very  poisonous. 

Sumach. — This  tree  is  the  rhus  glcdjvmn^  or  Pennsyl- 
vania sumach,  indigenous  to  Asia,  but  growing  wild  in 
Spain,  Portugal,  and  throughout  the  United  States.  It 
is  a  shrub  of  from  four  to  twelve  feet  in  height,  with 
crooked  stem  and  reddish-gray  bark,  and  differs  from  the 
poisonous  species.  The  new  leaves  are  green  on  the 
upper,  and  whitish  upon  the  under  surface,  but  they  be- 
come red  in  the  autumn.  The  flowers  are  greenish-red, 
and  bloom  in  July,  and  the  fruit,  which  consists  of  clus- 
ters of  small  crimson  berries,  ripens  in  the  fall.  Both 
the  leaves  and  the  bark  contain  tannin.  So  also  do  the 
warty  excrescences  which  grow  under  the  leaves.  Su- 
mach is  used  largely  for  tanning  in  this  country  and 
abroad.  In  some  cases  it  is  mixed  with  oak  bark,  and 
in  others  is  employed  alone,  as  in  the  manufacture  of 
morocco  and  glazed  skins,  for  which  purpose  it  is  pecu- 


92 


BARKS. 


liarly  adapted,  by  reason  of  its  not  imparting  any  color. 
It  is  said,  however,  to  diminish  the  phability  of  the 
leather. 

There  are  several  varieties  of  sumach  met  with  in 
commerce.  The  most  esteemed  is  the  product  of  the 
rhiis  glabrum  or  coriariay  which  is  composed  of  the  leaves, 
peduncles,  and  young  shoots  thoroughly  mixed  and 
powdered. 

Sicily  sumach  is  in  high  repute.  It  is  in  bright-green 
powder,  with  astringent  taste  and  violet  odor.  Of  the 
two  varieties  of  this  species,  the  sumach  alcamo  is  pre- 
ferred for  morocco.  The  other,  which  is  feeble  in  tan- 
ning constituents,  is  only  used  for  dyeing  (Dumas  7, 
527). 

French  sumach  occurs  in  grayish-green  powder. 

The  preparation  of  sumach  consists  in  sun-drying  the 
branches,  separating  the  leaves  by  threshing  with  a  flail, 
and  then  grinding  them  in  a  mill.  When  packed  in 
bags,  it  is  then  ready  for  the  market.  Sometimes  the 
young  branches  are  ground  with  the  leaves  for  fraud- 
ulent purposes. 

Willow. — The  white  willow  [salix  cdha)  is  the  common 
European  willow,  which  is  found  growing  in  the  northern 
and  temperate  parts  of  North  America.  Its  bark  is 
easily  separable  in  the  summer,  and  when  dried,  is  of  an 
ash-gray  color  on  the  upper,  and  of  a  reddish  yellow  on 
the  under  surface.  It  is  brittle,  wdth  a  fibrous  fracture 
and  bitter  astringent  taste.  The  bark  of  the  branches 
is  thin,  and  in  drying  assumes  the  quill  form.  The  white 
willow  contains,  according  to  Davy,  2.295  per  cent,  of 
tannin,  and  the  Leicester  willow  6.86  per  cent.  The 
willow  genus  comprises  upwards  of  one  hundred  species, 
nearly  all  of  which  are  native  to  Europe  or  North  Ame- 
rica.   The  black  willow  {S.  nigra)  is  the  most  common 


BARKS. 


93 


American  willow,  and  grows  extensively  in  the  "Western 
and  Middle  States. 

In  the  north  of  Europe,  they  use  the  bark  of  S.  alba 
for  tanning;  and  in  Iceland,  that  of  the  S.  herbacea. 

The  leather  which  is  made  from  kid  and  lamb  skins, 
owes  its  agreeable  odor  to  the  willow  bark  with  which  it 
is  tanned. 

Sycamore. — The  bark  of  the  acer  pseudo-jplatanuSj 
growing  throughout  the  United  States,  south  of  Maine, 
and  abounding  in  the  fertile  valleys  of  the  West.  It 
takes  the  name  of  buttonwood,  sycamore,  plane-tree,  and 
water-beech,  according  to  locality.  The  bark  contains 
2.3  of  tannin. 

Tamarish. — The  tamarisk  {tamarix  gallicd)  is  a  hardy 
shrub-plant,  indigenous  to  Spain,  Italy,  and  the  south  of 
France.  Its  leaves  resemble  those  of  the  savin-tree,  but 
are  of  a  lighter  green  color.  The  bark  is  deep  reddish- 
brown  on  the  upper,  and  yellowish  on  the  under  side. 
Both  the  wood  and  bark  have  an  astringent,  slightly 
bitter  taste.  The  bark  should  be  taken  from  branches 
of  two  to  four  years'  growth. 

Winters  Baric. — The  product  of  an  evergreen  tree 
(drymis  winteri,  orwinterana  aromatica),  indigenous  to  all 
South  America,  but  growing  chiefly  in  Brazil.  The  bark 
is  of  a  gray  color,  inclining  to  reddish,  and  reaches  mar- 
ket in  flat  and  very  large  pieces,  or  in  quills  of  about 
twelve  inches  in  length,  and  an  inch  or  more  in  diameter. 
It  has  always  the  appearance  of  having  been  scraped 
externally,  and  breaks,  with  a  grayish  color  of  the  outer 
fracture,  while  that  of  the  internal  part  is  reddish.  It 
has  a  sharp  burning  taste  and  terebenthine  odor.  Henry 
found  tannin  among  its  constituents. 

Tulip'Tree. — The  bark  of  the  poplar  {Jiiriodendron  iu- 
lipi/era)  also  contains  tannin.    This  tree  grows  through- 


94 


BARKS. 


out  the  United  States.  The  bark  is  grayish-brown  with 
the  epidermis,  and  yellowish-white  without  it.  It  is 
brittle,  heavy,  and  has  a  disagreeable  odor,  and  a  pun- 
gent, aromatic  taste,  which  it  loses  by  age. 

SL  Lucia  Bark. — This  bark  is  the  product  of  the  ex- 
ostemma  florihunda,  and  is  said  to  be  suitable  for  tan- 
ning. 

Wattle  Barh. — The  bark  of  the  different  species  of 
mimosa,  growing  abundantly  in  Australia  and  New  Zea- 
land. Sometimes  a  fluid  extract  of  the  bark  is  imported. 
The  leather  tanned  with  wattle  bark  is  of  excellent 
quality,  but  highly  colored. 


CHAPTER  VII. 

OAK-BARKS. 

The  oak-tree,  from  its  majestic  appearance,  great 
strength,  hardiness,  and  durability,  has  been  termed  the 
"  patriarch  of  the  forest,"  and  is  considered  as  the  em- 
blem of  grandeur.  It  is  said  to  live  from  three  to  five 
hundred  years,  and  is  the  most  valuable  of  trees  for  its 
wood  as  well  as  bark. 

The  oak  is  indigenous  throughout  Britain  and  North 
America.  There  are  many  species,  and  all  contain  a 
large  amount  of  tannin  in  their  bark,  leaves,  and  fruit. 
The  bark  is  gathered  from  May  to  J uly,  because  it  con- 
tains more  tannin  in  the  spring  than  at  any  other 
season. 

Skins  may  be  converted  into  leather  more  or  less  per- 
fectly, by  the  action  of  any  of  the  vegetable  substances 
which  contain  tannin ;  but  the  small  quantity  of  it  ex- 
isting in  most  of  them,  and  the  costliness  and  rarity  of 
those  of  which  it  is  a  principal  constituent,  together  with 
the  injurious  effects  upon  the  leather  which  often  attend 
their  use,  have  restricted  the  substitution  of  other  sub- 
stances for  oak-bark,  which  tanners  have  employed  from 
the  earliest  times,  and  which,  when  ground,  seems  to 
present  the  tannin  to  the  skins  exactly  in  the  proportion 
and  under  the  circumstances  best  calculated  to  effect  their 
conversion  into  superior  leather. 


96 


EUROPEAN  BARKS. 


More  than  eighty  species  of  the  oak  are  known,  of 
which  at  least  one-half  inhabit  the  United  States,  and 
the  elevated  portions  of  Mexico.  The  bark  of  all  the 
species  abounds  in  tannin  and  gallic  acid,  and  is,  or  may 
be  used  in  tanning;  but  in  Europe,  that  of  different  va- 
rieties of  quercus  rohur,  and  of  the  quercus  coccifera^  and 
in  America,  the  bark  of  quercus  falcatay  quercus  rubra, 
quercus  tinctoria,  and  quercus  j>rinus  monticola  are  most 
esteemed  for  the  purpose.  We  proceed  to  give  a  short 
account  of  these,  and  of  a  few  other  American  species 
which  are,  or  may  be  used  to  furnish  bark  suitable  for 
the  purposes  of  the  tanner. 

EUROPEAN  OAKS. 

1.  Quercus  Rohur. — The  common  European  oak,  or 
British  oak,  as  it  is  commonly  called,  is  a  tree  of  the 
utmost  importance  on  account  of  its  general  distribution 
throughout  Europe,  and  the  excellent  qualities  of  its 
wood  and  bark.  The  term  rohur  is  used  by  most  au- 
thors to  designate  a  group  of  closely  allied  species,  or 
perhaps  only  varieties;  the  two  principles  of  which,  the 
Q.pedunculata,  and  the  Q.  sessiliflora,  which  are  too  much 
alike,  in  magnitude  and  general  appearance,  to  require 
a  separate  description,  are  both  widely  spread.  They 
are  majestic  trees,  attaining  the  height  of  from  sixty  to 
a  hundred  feet,  with  trunks  from  six  to  twelve  or  more 
feet  in  circumference;  with  spreading  tortuous  branches 
and  spray,  and,  when  standing  singly,  with  heads  usually 
broader  than  they  are  high.  The  leaves  are  deciduous, 
oblong,  smooth,  dilated  upwards;  with  sinuses  rather 
acute,  and  lobes  obtuse;  stalks  of  the  fruit  elongated; 
nuts  oblong.  The  leaves  resemble,  in  form  and  appear- 
ance, those  of  the  American  white  oak.     Except  in 


EUROPEAN  OAKS. 


97 


the  north  of  Russia,  and  in  the  limited  districts  of 
France,  where  the  Q.  cocci/era  is  used,  the  bark  from 
the  varieties  of  this  oak  is  exclusively  employed  in 
the  manufacture  of  leather;  and  that  from  the  small 
branches  is  preferred,  because  in  them  the  epidermis  is 
thinner  and  the  cellular  integument  which  contains  the 
tannin  is  more  abundant. 

2.  Quercus  Cocci/era. — The  Kermes  oak  is  a  tortuous, 
branching  shrub,  inhabiting  Spain,  Portugal,  and  the 
South  of  France.  It  grows  to  the  height  of  from  three 
to  four  and  a  half  feet,  in  close,  thick  tufts,  or  clumps, 
which,  by  the  interlacing  of  their  matted  roots,  consoli- 
date the  soil  around  them,  and  prevent  it  from  being 
washed  away  by  the  heavy  rains  prevailing  in  its  native 
localities. 

The  leaves  are  elliptic-oblong,  rigid,  smooth  on  both 
sides,  with  spreading,  bristly,  spinous  teeth;  fruit  on  pe- 
duncles ;  nut  ovate ;  calyx  with  spreading,  pointed,  some- 
what recurved  scales.  The  whole  plant  resembles  a 
holly  in  miniature ;  but  the  leaves  are  of  a  paler  green. 

The  bark  of  the  root  is  of  a  yellowish-brown  color, 
and  is  very  rich  in  tannin.  This  species  of  oak  is  chiefly 
known  from  its  being  fed  upon  by  the  coccus  ilicis,  a  little 
insect,  resembling  in  appearance  a  red  berry,  which  fur- 
nishes a  scarlet  dye,  highly  valued  in  commerce  before 
the  introduction  of  cochineal ;  but  it  is  also  worthy  of 
notice  on  account  of  the  bark  of  the  root,  which  is  em- 
ployed for  tanning  to  a  considerable  extent  in  various 
parts  of  France.  It  is  there  called  garronille,  and  is 
said  to  abound  in  tannin,  and  to  be  used  with  great  ad- 
vantage in  the  tanning  of  a  very  superior  quality  of 
thick,  impervious  sole-leather. 


98  AMERICAN  OAKS. 


AMERICAN  OAKS. 

3.  Quercus  Falcata. — This  oak,  known  in  Delaware, 
Maryland,  and  Virginia  by  the  name  of  Spanish  oak, 
and  in  the  Carolinas  and  Georgia  by  that  of  red  oak^  is 
a  large  tree,  inhabiting  all  those  parts  of  the  Union  which 
are  south  of  the  forty-first  parallel  of  latitude,  but  most 
abundant  in  the  Atlantic  States. 

This  oak  is  remarkable  from  the  great  dissimilitude 
which  exists  in  its  leaves  and  general  appearance  in 
different  climates.  In  the  southern  States  it  grows  to 
the  height  of  eighty  feet,  with  a  trunk  four  or  five  feet 
in  diameter;  while  in  New  Jersey  it  is  never  above 
thirty  feet  high,  with  a  trunk  four  or  five  inches  thick. 
The  bark  is  thick,  black,  and  deeply  furrowed,  and  the 
wood  is  reddish  and  cross-grained,  with  open  pores.  The 
leaves  on  the  trees  in  the  South  are  falcate,  and,  as  well 
as  the  young  shoots  to  which  they  are  attached,  are 
covered  with  a  thick  down  upon  the  under  sides.  In 
New  Jersey  the  leaves  are  three-lobed,  except  a  few 
upon  the  summit,  which  are  slightly  falcated.  This  tree 
fructifies  once  in  two  years.  Its  flowers  put  forth  in  May, 
and  are  succeeded  by  small,  round,  brown  acorns,  con- 
tained in  scaly,  shallow  cups,  supported  by  peduncles  one 
or  two  lines  in  length.  They  resemble  those  of  the  bear- 
oak,  and  preserve,  for  a  long  time,  the  capability  of 
germination.  The  Spanish  oak  is  chiefly  valuable  on 
account  of  its  bark,  which  is  preferred  to  any  other  for 
tanning  coarse  leather,  which  it  is  supposed  to  render 
whiter  and  more  supple.  The  quality  of  the  leather 
prepared  with  it  is  said  to  be  improved  by  the  addition 
of  a  small  quantity  of  hemlock  bark  to  the  tan. 

4.  Quercus  Euhra. — The  red  oak  is  one  of  the  most 


AMERICAN  OAKS. 


99 


common  species  in  the  northern  States  and  in  Canada. 
It  is  very  abundant  in  the  lower  part  of  New  York,  in 
New  Jersey,  the  upper  districts  of  Pennsylvania,  and 
along  the  whole  range  of  the  Alleghanies. 

It  grows  to  a  large  size,  being  often  eighty  feet  high, 
and  three  or  four  in  diameter.  .  Its  leaves  are  large  and 
deeply  laciniated,  smooth  and  shining  on  both  sides,  and 
rounded  at  the  base.  On  the  middle  or  summit  of  the  full- 
grown  tree,  they  resemble  the  leaves  of  the  Spanish  oak, 
but  unlike  them  are  not  downy  beneath.  The  fructifica- 
tion is  biennial  and  it  flowers  in  May.  The  acorns  are 
large  and  numerous,  compressed  at  the  base,  rounded  at 
the  summit,  and  contained  in  flat  cups,  covered  with 
compact,  narrow  scales. 

The  bark  of  this  tree  consists  of  a  very  thin  epider- 
mis, with  a  thick,  cellular  integument.  It  is  very  gene- 
rally employed  in  tanning,  but  is  considered  inferior  to 
that  of  the  Spanish,  black,  and  rock-chestnut  oaks. 

5.  Quercus  Prinus  Monticola. — The  roch-cJiestnut  oalz  is 
most  frequently  met  with  in  the  middle  and  some  parts 
of  the  northern  States,  but  is  rarely  found  along  with 
other  trees  in  the  forest,  but  only  on  high  grounds  thickly 
covered  with  stones  or  rocks.  Along  the  Alleghanies, 
it  often  constitutes  nine-tenths  of  the  growth  upon  some 
of  the  mountains.  In  Pennsylvania,  Virginia,  and  Mary- 
land, it  is  called  cJiestnut-oah,  on  account  of  the  resem- 
blance of  the  bark  to  that  of  the  chestnut;  and  on  the 
banks  of  the  Hudson  and  the  shores  of  Lake  Champlain, 
it  is  known  as  the  rock  oah,  from  the  situations  in  which 
it  is  found.  The  rock-chestnut  oak,  when  growing  in  a 
fertile  soil,  is  often  sixty  feet  high,  and  three  feet  in  di- 
ameter; but  usually  growing  in  sterile  soil,  it  rarely 
attains  these  dimensions.  The  leaves  are  five  or  six 
inches  long,  and  three  or  four  broad;  oval,  and  uniformly 


100 


AMERICAN  OAKS. 


denticulated.  When  opening  in  the  spring,  they  are 
covered  with  a  thick  down ;  but  when  expanded,  they 
are  perfectly  smooth  and  whitish  beneath.  The  flowers 
appear  annually  in  the  month  of  May,  and  are  succeeded 
by  brown  acorns  of  an  oblong  oval  shape,  and  sometimes 
an  inch  in  length,  a  third  part  of  which  are  contained  in 
spreading  cups  with  loose  scales. 

When  the  trunk  of  this  tree  is  more  than  a  foot  in 
diameter,  it  is  covered  with  a  thick,  hard,  deeply-furrowed 
bark.  The  epidermis  is  strongly  impregnated  with  the 
tanning  principle,  which  in  other  species  resides  chiefly 
in  or  under  the  cellular  integument.  The  bark  is  esteemed 
as  among  the  best  for  tanning,  in  Pennsylvania  and  New 
York;  but  only  that  of  the  secondary  branches,  and  of 
the  trunks  of  young  trees,  is  employed. 

6.  Quercus  Tlnctoria. — The  black  or  quercitron  oak  is 
a  large  tree,  found  throughout  the  United  States,  south 
of  latitude  43°,  and  abundantly  in  the  middle  States, 
and  in  the  upper  parts  of  the  Carolinas  and  Georgia.  It 
is  one  of  the  loftiest  trees  of  the  American  forests,  being 
often  eighty  or  ninety  feet  high,  and  four  or  five  in  dia- 
meter. The  trunk  is  covered  with  a  deeply  furrow^ed 
bark  of  medium  thickness,  and  of  a  deep-brown  or  black 
color,  which  in  the  North  serves  to  distinguish  it  from 
the  red,  scarlet,  and  gray  oaks,  when  the  leaves  have 
fallen ;  but  as  the  bark  of  the  Spanish  oak  in  the  South 
is  of  the  same  color,  all  doubt  of  its  identity  may  be  re- 
moved by  chewing  a  piece  of  the  cellular  integument, 
that  of  the  quercitron  being  very  bitter,  and  imparting 
a  yellow  color  to  the  saliva,  which  is  not  the  case  with 
the  other.  The  leaves  are  large,  deeply  laciniated,  and 
divided  into  four  or  five  lobes.  They  are  like  those  of 
the  scarlet  oak ;  but,  during  the  summer,  have  their  sur- 
faces roughened  with  small  glands  which  are  evident  to 


AMERICAN  OAKS. 


101 


the  eye  and  the  touch.  The  fructification  is  biennial 
and  occurs  in  May.  The  acorns  usually  grow  in  clusters, 
are  of  a  brown  color,  sub-sessile,  and  half  buried  in  a 
thick,  scaly  cup. 

The  quercitron,  so  much  used  in  dyeing,  is  obtained 
from  the  cellular  integument;  and  the  bark  is  very  ex- 
tensively employed  in  tanning,  for  which  it  is  well 
adapted,  as  it  is  produced  in  great  abundance  and  is 
rich  in  tannin.  The  only  inconvenience  is,  that  shoes 
made  of  leather  tanned  with  it  are  apt  to  impart  a  yel- 
low tinge  to  the  stockings.  This  color  of  the  leather 
does  not  increase  its  value,  as  has  been  stated  by  some 
authors,  and  is  often  removed  by  a  particular  process. 

7.  Quercus  Alba. — The  white  oak  is  found  throughout 
the  United  States,  being  widely,  but  unequally  distri- 
buted from  about  latitude  46°,  to  Florida,  and  from  the 
Atlantic  to  some  distance  beyond  the  Mississippi  River; 
extending  somewhat  further  northward  in  these  western 
regions.  It  is  most  abundant  in  Virginia  and  in  the 
middle  States,  particularly  in  the  southwestern  part  of 
Pennsylvania,  upon  the  Monongahela  and  its  branches, 
where  it  sometimes  composes  nine-tenths  of  the  forest. 

The  white  oak  reaches  the  elevation  of  seventy  or 
eighty  feet,  with  a  diameter  of  six  or  seven  feet.  The 
leaves  are  regularly  and  obliquely  divided  into  oblong, 
rounded  lobes,  destitute  of  points.  Soon  after  unfolding, 
they  are  reddish  above,  and  white  and  downy  beneath, 
but,  when  full  grown,  they  are  smooth  and  of  a  light 
green  above,  and  glaucous  below.  The  leaves  change 
in  autumn  to  a  bright-violet  color,  and  a  few  of  the  dried 
leaves  persist  till  the  circulation  is  renewed  in  the  spring. 
The  tree  is  easily  distinguishable-  in  winter  by  this  pecu- 
liarity, and  by  the  whiteness  of  its  bark.  It  puts  forth 
flowers  in  May,  which  are  succeeded  by  oval  acorns, 


102 


AMERICAN  OAKS. 


large,  very  sweet,  contained  in  rougb,  shallow,  grayish 
cups,  and  borne  singly,  or  in  pairs,  by  peduncles  eight  or 
ten  lines  long,  attached  to  the  shoots  of  the  season. 

The  bark  is  often  variegated  with  large  black  spots, 
and,  on  trees  of  less  than  sixteen  inches  in  diameter,  the 
epidermis  is  divided  into  squares ;  on  old  trees,  growing 
in  moist  grounds,  it  is  in  the  form  of  plates,  laterally 
attached.  The  bark  is  considered  by  many  tanners  to 
be  the  best  for  preparing  leather  for  saddles  and  similar 
objects;  but  it  is  little  emploj^ed,  as  that  from  the  trunk 
and  large  limbs  alone  is  used,  and  on  these  the  cellular 
integument  is  much  thinner  than  it  is  on  those  of  the 
red  oak.  The  inner  bark  of  the  small  branches  con- 
tains the  greatest  quantity  of  tannin. 

8.  Qiiercus  Coccinm. — The  scarlet  oak  is  most  abund- 
ant in  the  middle  States,  and  on  the  mountains  of  Caro- 
lina and  Georgia,  but  is  found  as  far  north  as  latitude 
43°.  It  grows  to  more  than  eighty  feet  in  height,  and 
three  or  four  in  diameter.  The  leaves,  w^hich  are  sup- 
ported by  long  petioles,  are  of  a  beautiful  green  color, 
shining  on  both  sides  and  remarkably  laciniated,  having 
usually  four  deep  sinuses,  which  are  very  broad  at  the  bot- 
tom. They  change  with  the  first  cold,  and  after  several 
frosts  become  of  a  bright  scarlet  color.  It  fructifies 
biennially,  flowering  in  May.  The  acorns  are  large, 
similarly  rounded  at  both  ends,  and  half  covered  with 
scaly  cups.  The  tree  produces  galls,  which  are  applied 
to  the  same  purposes  as  the  European  galls  of  com- 
merce. 

The  bark  of  the  scarlet  oak  is  very  thick,  and  is  gene- 
rally employed  in  tanning,  though  it  is  not  preferable  to 
that  of  the  red  and  gray  oaks. 

9.  Quercus  Ambigua. — The  gray  oak  is  abundant  in 
Maine,  New  Hampshire,  and  on  the  shores  of  Lake 


AMERICAN  OAKS. 


103 


Champlain  in  Vermont.  It  attains  a  height  of  fift}^  or 
sixty  feet,  and  a  diameter  of  fifteen  or  eighteen  inches. 
The  leaves  are  large,  smooth,  and  deeply  sinuated  at 
right  angles  to  the  main  ribs.  The  flowers  put  forth  in 
May,  and  are  succeeded  by  acorns  of  a  middling  size, 
rounded  at  the  end  and  contained  in  scaly  cups.  The 
wood  and  bark  are  similar  to  those  of  the  red  oak,  and 
the  latter  may  be  employed  in  tanning. 

10.  Quercus  Virens. — This  species,  known  as  the  live 
oaJc,  is  confined  to  the  vicinity  of  the  Atlantic  coast,  south 
of  latitude  37°,  and  of  the  Gulf  of  Mexico  as  far  as  the 
Sabine  River,  being  never  found  more  than  twenty  miles 
inland.  It  is  commonly  forty  or  fifty  feet  high,  and  one 
or  two  feet  in  diameter.  The  leaves  are  oval,  coriaceous, 
of  a  dark  green  color  above,  and  w^hitish  beneath,  per- 
sisting during  several  years,  and  being  partially  renewed 
every  spring.  It  fructifies  once  in  two  years,  the  flowers 
appearing  in  May,  and  being  succeeded  by  acorns  of  an 
oval,  lengthened  form,  nearly  black,  and  contained  in 
shallow,  grayish,  pedunculated  cups. 

The  bark  is  hard  and  thick,  and  of  a  blackish  color. 
It  is  very  excellent  for  tanning  leather,  but  is  not  largely 
employed  for  the  purpose. 

The  bark  from  a  number  of  other  species  of  American 
oaks  may  be  and  is  incidentally  employed  in  tanning, 
but  manufacturers  of  leather  in  the  United  States  make 
use  almost  entirely  of  those  which  have  been  described, 
and  particularly  of  the  first  four  kinds. 


CHAPTEE  VIII. 


BARKING  OF  TREES. 

The  four  distinct  layers  of  which^  as  we  have  already 
stated^  bark  is  composed,  are  not  equally  rich  in  tannin. 
Indeed,  the  epidermis  contains  none,  and  the  liber  very 
little.  It  exists  chiefly  in  the  inner  layers  of  the  cortex, 
or  true  bark;  extractive  matter  predominating  in  the 
middle-colored  portion.  Davy  found  that  the  bark  of  a 
medium-sized  oak  contained  6.04  per  cent,  of  tannin, 
while  the  external  layers  gave  only  1.50. 

Barks  with  thick  epidermis  are  the  least  valuable  in 
tanning  ingredients. 

It  is  a  mooted  point  whether  the  quantity  of  tannin  in- 
creases with  the  age  of  the  bark.  Fontenelle  and  Male- 
peyre  say  that  the  older  the  bark  the  more  of  tannin  it 
contains,  and  in  support  of  their  opinion  they  cite  the 
European  and  American  practice  of  collecting  the  bark 
chiefly  from  the  maturer  trees. 

The  proper  season  for  separating  the  bark  from  trees 
is  in  the  spring  of  the  year,  when  the  sap  is  circulating 
most  actively,  and  before  the  complete  expansion  of  the 
leaf  Davy  found  that  the  bark  of  oak  trees,  cut  in  the 
spring,  contained  nearly  one-third  more  of  tannin  than 
that  obtained  in  the  autumn,  thus  proving  the  advantage 
of  cutting  the  trees  in  the  former  season.  The  proper 
time  for  barking  the  oak  in  this  country  is  from  the  end 


BARKING  OF  TREES. 


105 


of  April  to  the  end  of  June,  varying  with  the  degree  of 
latitude,  the  exposure  of  the  locality,  and  the  tempera- 
ture of  the  season  which  has  preceded  the  cutting. 
The  operation  should  be  postponed  until  after  the  usual 
time  of  harvesting  the  bark,  if  the  previous  winter  has 
been  uncommonly  severe  or  prolonged,  and  should  be 
anticipated,  if  a  mild  season  has  caused  an  early  cir- 
culation of  the  sap.  In  our  northern  States,  the  bark 
does  not  generally  acquire  its  full  strength  of  tannin,  nor 
is  it  proper  to  gather  it  until  the  middle  of  May,  and 
in  some  places  not  until  June.  In  lower  latitudes,  and 
in  a  warm  spring  succeeding  a  mild  winter,  it  may  be 
harvested  as  early  as  April.  The  bark  of  southern  oaks 
yields  generally  more  tannin  than  that  of  those  growing 
in  higher  latitudes ;  and  that  of  trees  in  dry  and  elevated 
places,  with  a  warm  exposure,  is  superior  to  the  bark 
taken  from  oaks  growing  in  low,  damp,  and  shady  loca- 
tions. Wet  seasons  have  likewise  an  influence  in  dimi- 
nishing the  tanning  power  of  bark. 

The  process  of  barking  is  in  general  well  understood. 
Immediately  after  the  tree  is  felled,  the  bark  is  cut  across 
circularly  at  the  two  extremities  of  the  trunk,  and  is  then 
split  off  in  longitudinal  pieces  of  the  proper  size,  and 
dried  slowly  in  the  shade.  The  greatest  attention  should 
be  paid  to  harvesting  it  properly,  as  it  loses  color  and 
becomes  mouldy  and  otherwise  injured  in  quality,  if 
suffered  to  heat  or  ferment.  The  best  mode  is  to  make 
what  are  called  by  foresters  temporary  lofts^  about  two 
feet  wide,  and  long  enough  to  hold  a  day's  peeling  of 
bark.  These  lofts  are  made  by  driving  uprights  of  forked 
stakes  into  the  ground,  three  feet  high  in  the  back  row, 
and  two  and  a  half  in  the  front,  and  a  sloping  floor  is 
laid  upon  these  by  placing  loppings  between  the  forks  of 
the  bearers.  The  bark  is  then  laid  upon  this  floor,  with 
8 


106 


BARKING  OF  TREES. 


the  thick  ends  towards  the  highest  side ;  the  smaller  bark 
is  placed  over  this  to  the  height  of  six  or  eight  inches, 
and  the  broad  pieces  are  laid  over  the  whole,  to  protect 
it  from  rain  or  djew.  The  pieces  should  be  turned  in  four 
or  five  days,  in  order  to  prevent  moulding ;  and  in  about 
ten  days,  they  will  be  sufficiently  dry  to  be  stacked  until 
wanted  by  the  tanner.  The  stack  should  not  exceed 
eight  feet  in  width,  in  order  that  fermentation  may  not 
occur,  and  it  should  be  covered  with  a  roof  formed  and 
thatched  like  that  of  a  hay  or  corn  stack. 


CHAPTER  IX, 


METHODS  OF  ESTIMATING  THE  TANNING  POWER  OF 
ASTRINGENT  SUBSTANCES. 

The  quality  of  bark  may  be  determined  by  inspection ; 
but  a  chemical  examination  alone  will  enable  us  to  esti- 
mate accurately  its  degree  of  excellence. 

A  good  bark  may  be  recognized  by  its  color.  That  is 
good  which  is  white  on  the  outer  surface,  and  reddish  in 
the  interior :  which  is  rough,  dry,  fragile,  and  with  a  clean 
fracture,  free  from  fibres.  The  astringency  of  its  taste, 
and  its  odor  should  be  decisive,  more  particularly  when 
it  is  ground. 

When  the  epidermis  and  liber  are  dry,  thick,  and 
blackish,  and  channelled  with  large  crevices,  the  bark 
is  of  inferior  quality.  These  old  barks  are  in  an  incipi- 
ent state  of  decomposition ;  as  is  also  the  case  with  bark 
which  has  been  long  exposed  to  dampness. 

Bark  internally  of  a  red  color,  which  has  become 
nearly  inodorous,  dingy  and  rusty,  has  likewise  depre- 
ciated in  useful  properties. 

The  determination  of  the  quality  of  bark  by  chemical 
means,  is  based  upon  the  separation  of  the  tannin,  that 
component  upon  which  its  value  as  tanning  material  ex- 
clusively depends.  The  requisite  manipulations  are  as 
follows : — 

We  have  already  mentioned  the  fact  that  a  character- 
istic behavior  of  gelatine  is  to  form  an  insoluble  com- 


108 


THE  TANNING  POWER  OF 


pound  with  tannin,  which  is  entirely  distinct  in  properties 
from  its  constituents  in  their  original  states.  Upon  this 
reaction  depends  the  whole  theory  and  practice  of  the 
tanner's  art. 

To  ascertain  the  relative  value  of  barks,  or  tanning 
substances,  it  is  only  necessary  to  determine  the  ratio,  by 
weight,  of  the  precipitates  thrown  down  by  gelatine  from 
aqueous  infusions  of  equal  weights  of  the  materials.  These 
precipitates,  separated  by  filtration  and  dried,  give,  by  the 
differences  in  weight,  the  relative  proportions  of  tannin. 

Davys  Process. — Davy's  process  is  to  digest  460  grains 
of  the  powdered  bark  in  a  pint  of  boiling  water,  and 
after  a  day's  repose,  and  frequent  stirring  during  the  in- 
terval, to  filter.  The  filtrate  is  then  mixed  with  an  equal 
volume  of  a  liquid  made  by  dissolving  60  grains  of 
gelatine,  or  pure  isinglass,  in  two  pints  of  hot  water,  and 
the  mixture  is  then  filtered.  The  precipitate  on  the 
filter  is  to  be  dried  in  the  air  and  accurately  weighed. 
As  the  precipitates  of  gelatine  by  tannin,  when  dry, 
average  40  per  cent,  of  tannin,  it  is  easy  to  obtain  an 
approximate  result  by  calculation.  For  example,  sup- 
pose the  precipitate  weighs  150  grains,  then  as 

100  :  40  :  :  150  :  60  =  the  amount  of  tannin  in  the  460 
grains  of  bark  operated  upon,  or  13.04  per  cent. 

Bostock  is  convinced  that  the  precipitate  of  gelatine  by 
tannin,  in  the  above  process,  is  so  intimately  suspended 
through  the  liquid  as  to  render  its  entire  separation  by 
filtering  almost  impossible,  a  portion  always  passing 
through  the  filter.  At  the  same  time,  the  proportion  of 
tannin  which  it  contains  is  not  uniform,  as  that  which 
goes  down  first  carries  about  50  per  cent. ;  while  that 
which  ensues  takes  scarcely  any  with  it.  Acting  upon 
these  suggestions.  Bell  Stephens  proposed  the  following 
improvement  upon  Davy's  method : — 


ASTRINGENT  SUBSTANCES. 


109 


Bell  Stephens  s  Process. — Small  strips  of  hides  are  to  be 
soaked  for  some  hours  in  a  weak  solution  of  tanning  ma- 
terial, made  with  water  at  90°  F.  In  from  8  to  10  hours 
the  whole  of  the  tannin  is  abstracted,  and  the  increase 
of  the  weight  of  the  strips,  thus  acquired,  will  indicate 
the  precise  amount  absorbed  by  them. 

The  strips  must  be  weighed  in  a  dry  state ;  but  before 
they  are  placed  in  the  tanning  liquor,  they  should  be 
softened  by  being  soaked  in  warm  water,  and  by  work- 
ing with  the  fingers,  so  as  to  facilitate  the  subsequent 
absorption  of  the  tanning  principle.  When  they  are 
taken  out,  drying  must  precede  the  final  weighing.  The 
best  skins  for  this  essay  are  sound  fresh  ox  hides,  shaved 
to  the  greatest  possible  degree  of  thinness. 

Though  Davy's  method  is  not  faultless,  it  is  preferable 
to  that  of  Stephens,  which,  owing  to  the  unequal  ab- 
sorption of  water  by  the  skin  at  different  times,  cannot 
give  the  exact  amount  of  tannin. 

A  thorough  examination  of  all  the  parts  of  the  several 
species  of  oak  at  different  stages  of  their  growth,  showing 
the  comparative  value  in  tanning  principle,  under  differ- 
ent circumstances,  would  be  interesting  to  the  tanner  as 
well  as  satisfactory  to  the  man  of  science. 

Warrington  s  Process. — The  following  method,  as  com- 
municated by  the  author,  is  taken  from  the  memoirs  of 
the  London  Chemical  Society,  1847  : — 

"  Gelatine  was  selected  as  the  basis  for  the  estimation 
of  their  comparative  value ;  and  after  several  trials  with 
various  kinds  of  natural  and  manufactured  gelatine,  such 
as  varieties  of  isinglass,  glue,  patent  gelatine,  &c.,  the 
finest  long  staple  isinglass  was  found  to  be  the  most 
constant  in  its  quality  and  least  liable  to  undergo  change. 

"  With  this,  therefore,  the  test  solution  was  prepared, 
of  such  a  strength  that  each  division,  by  measure  in  the 


110 


THE  TANNING  POWER  OF 


ordinary  alkaliraeter  tube,  should  be  equivalent  to  the 
one-tenth  or  one-fourth  of  a  grain  of  pure  tannin,  and 
thus  the  number  of  divisions  used  would  indicate  the  pro- 
portion of  available  tannin,  or  substance  precipitable  by 
gelatine  contained  in  any  specimen.  A  given  weight  of 
the  sample  under  trial  was  then  infused  in  water,  or,  if 
necessary,  the  astringent  matter  extracted  by  boiling, 
and  the  clear  liquid  precipitated  by  the  test  solution 
until  no  further  deposit  occurred. 

"  It  was  necessary  in  the  course  of  this  operation  to  test 
at  intervals  a  portion  of  the  solution  under  examination, 
to  ascertain  the  progress  of  the  trial;  and  this,  from  the 
nature  of  the  precipitate,  was  attended  at  first  with  some 
little  difficulty;  paper  filters  were  inadmissible  from  the 
quantity  of  the  solution  they  would  absorb,  and  thus 
introduce  a  source  of  extensive  error;  subsidence  ren- 
dered the  operation  very  tedious.  The  plan  I  have 
adopted  is  as  follows :  A  piece  of  glass  tubing,  about 
twelve  inches  in  length,  and  about  half  an  inch  internal 
diameter,  is  selected,  and  this  has  a  small  piece  of  wet 
sponge  loosely  introduced  into  its  lower  extremity,  and 
when  it  is  wished  to  abstract  a  part  of  the  fluid  under 
investigation,  for  a  separate  testing,  this  is  immersed  a 
few  seconds  in  the  partially  precipitated  solution;  the 
clear  liquid  then  filters  by  ascent  through  the  sponge 
into  the  tube,  and  is  to  be  decanted  from  its  other  ex- 
tremity into  a  test  glass ;  if,  on  adding  a  drop  of  the 
gelatine  solution  to  this,  a  fresh  precipitate  is  caused,  the 
whole  is  returned  to  the  original  bulk,  and  the  process 
proceeded  in,  and  so  on  until  the  operation  is  perfected ; 
this  method  of  operation  is  facilitated  by  conducting  the 
examination  in  a  deep  glass.  After  a  few  trials  the 
manipulation  will  be  found  exceedingly  easy,  and  in  this 
way  considerable  accuracy  may  be  arrived  at." 


ASTRINGENT  SUBSTANCES.  Ill 


Table  of  the  Average  Quantity  of  Tannin  in  different  Suhstances. 


Substances. 

Percentage 
of  tannin. 

Authority. 

CatechU;  Bombay  .... 

■  55.0 

Davv. 

"       Bengal  .... 

44.0 

T^.hataTiv  root, 

PpsphipT* 

u  u 

38.3 

C.  Gr.  Gmelin. 

Kino  (^tanniii  and  extractive) 

75.0 

Vanquelin . 

Tilltpa,  O'llin  fhiifpn  'fvnvirlntn    nr  rlhnJi'- 

tree')  ...... 

73.2 

E.  Solly. 

Nutgallsj  Aleppo 

65.0 

Gruibourt. 

Chinese  . 

69.0 

Bley. 

Xo  LI  ictl-l          f              •              .  . 

94  0 

TinnPT 

XiULlL/l . 

Oakj  old^    white  inner  bark 

21.0 

Cadet  de  Gassincourt. 

u      u            (c           a          _  ^ 

14.2 

Davv. 

Younff;                "         .  . 

15.2 

(( 

4  0 

a 

d-iUllC    Udl  A.  ... 

"Daw  and  rrPicpr 

Tin  w 

TCpTinpsi*  bjirl?       flip  mnf 

a 

T'prva  iflDonir^a,  or  trambir 
Avens  root  (jgeurn  urhanuni) 

40.0 

E<?PTiV)pnk 

41.0 

Tromsdorfif. 

Sauill  bulb 

24  0 

V  u^ei. 

Statlp(^   of  SmitVi  riarnlirifi 

12  4 

T^arrisili 

X  dx  1  lOUL. 

X^iX  L/li    Udl  JV           •               •               •               •  • 

Davy. 

u  u 

1  4 

jDiggers. 

Beech   

2.0 

Davv. 

•XJUjXVU  .... 

1.6 

XXdACl  ..... 

^  0 

O.  V 

li 

I  .npcifTrnf.    A  mPT'if'fin  vaco 

V^llCo Lil  Li JLA.iIJCX  Ivdll^   i  UOC                •  . 

rinr^pt  flp  rTa<!«;inpmit*t 

VydLlCw  IXC  \JI doOlUwL/Lii.  L. 

Carolina 

6.0 

a  a 

"       French  .... 

4.0 

Julia  de  Fontenelfe. 

"       Spanish,  white  inner  bark  . 

1.3 

Davy. 

"            "       colored  or  middle 

bark 

0.3 

a 

"            "      entire  bark 

0.5 

a 

"       horse  .... 

2.0 

Julia  de  Fontenelle. 

Poplar,  Lombardy  .... 

8.5 

a  a 

Black  thorn  

3.3 

Davy. 

Ash  bark  ..... 

3.8 

a 

Sassafras,  bark  of  the  root 

58.0 

Reinsch. 

Elm  

2.9 

Davy. 

Sumach,  Sicily  .... 

16.2 

u 

112  TANNIN  IN  DIFFERENT  SUBSTANCES. 


U.  U  o  t  ci  ii   ^  o  • 

Percentage 
of  tannin. 

A  nf  Ti  fw\  f  V 

XI.  KJl  ki±X  W  J.  i.  (j  V  ■ 

Sumach^  Malaga  .... 

16.4 

Daw. 

10.4 

Franck. 

Carolina  .... 

5.0 

Cadet  de  Gassincourt. 

"       Virginia  .... 

10.0 

Willow,  Leicester:  white  inner  bark  . 

16.0 

Davy. 

"          ^'        colored  or  middle 

bark 

3.1 

(( 

"                    entire  bark  . 

6.8 

a 

"          "        bark  of  the  trunk 

1.4 

BiffSfers. 

weeping  .... 

16.0 

Cadet  de  Grassincourt. 

Sycamore  bark  .... 

16.0 

a  a 

1.4 

Bie"P"ers. 

fee 

Elder        "  .... 

2.3 

Daw. 

Plum-tree  "  .... 

1.6 

Biffffers. 

Cherry-tree 

24.0 

Cadet  de  Grassincourt. 

"          Cornish  .... 

19.0 

a  a 

Tormentil  root  .... 

46.0 

ic  u 

Cornus  sanguinea  of  Canada 

44.0 

u  u 

Alder  bark  ..... 

36.0 

a  a 

Apricot  bark  ..... 

32.0 

a  u 

Pomegranate  bark  .... 

32.0 

u  a 

Bohemian  olive  .... 

14.0 

CC  iC 

Tan  shrub  with  myrtle  leaves,  bark  . 

13.0 

Service-tree  bark  (June  berry)  . 

18.0 

a  u 

Cloves  ...... 

15.0 

Davy. 

Winter's  bark  .... 

9.0 

Henry. 

CHAPTER  X. 

TAN,  OK  POWDERED  OAK-BARK. 

The  more  finely  divided  a  substance,  the  sooner  and 
more  readily  does  it  yield  to  the  action  of  the  liquid 
which  dissolves  its  constituents.  Water,  accordingly, 
dissolves  the  tannin  from  bark  in  powder  much  more 
readily  than  from  bark  in  coarse  pieces.  The  grinding 
of  the  bark  for  tanning  purposes  is,  therefore,  indispen- 
sable. It  must  not,  however,  be  reduced  to  impalpable 
fineness,  else  the  solvent  will  act  upon  it  too  rapidly. 
Very  fine  powders  also  form  a  compact  mass  when  wet, 
and  thus  obstruct  or  retard  the  infiltration  of  the  solvent 
liquid. 

Bark  is  ground  in  mills  varying  in  construction  in  dif- 
ferent countries,  and  driven  or  propelled  by  horse,  water, 
or  steam  power.  In  England,  it  is  crushed  between 
chasers,  or  stones.  There  is  a  mill  of  ingenious  construc- 
tion used  in  Salleron's  tannery  in  France,  but  as  its 
rapid  motion  so  modifies  the  bark  as  to  cause  it  to  impart 
color  to  the  hides,  we  omit  a  description  of  it. 

In  the  south  of  France  they  use  a  vertical  mill  of 
hard  stone,  similar  to  that  employed  for  crushing  oil 
seeds.  It  consists  of  two  vertical  stones  (Fig.  2),  of 
about  7 J  feet  in  diameter,  and  18  inches  in  thickness. 
The  axle  of  these  stones  is  fixed  in  a  frame  which  in- 
closes an  upright  shaft  turning  upon  a  pivot,  and  fixed 
in  the  centre  of  a  strong  stone  bed.    Rotary  motion 


114 


TAN. 


Fig.  2. 


being  communicated,  imparts  to  each  stone  a  double 
movement;  that  upon  the  other,  and  that  which  it  under- 
goes in  describing  a  circle  upon  the  stone  bed  upon 
which  it  rolls. 

The  axle  of  each  stone  should  be  so  adjusted  as  to 
allow  it  to  be  raised  or  lowered  according  to  circum- 
stances. One  of  the  stones  is  placed  nearer  to  the  verti- 
cal shaft  than  the  other,  so  as  to  give  a  greater  extent  of 
crushing  surface  beneath.  Two  followers  press  the  bark 
forward  under  the  stones,  and  a  cloth  is  attached  to  the 
outer  one,  for  the  purpose  of  rubbing  off  any  pieces  of 
bark  that  may  adhere  to  the  edges  of  the  stones. 

BagnalVs  Machine  for  Chopping  Bark  and  Fleshing 
Hides. — Fig.  3.  General  plan  of  the  mill. 

Fig.  4.  Longitudinal  section,  showing  the  elevation  of 
a  part  of  the  machinery. 

Fig.  5.  Section  across  part  of  the  mill. 

A  (Fig.  3) .  Part  of  an  undershot  wheel  moving  the 
machinery,  b.  Shaft  of  the  wheel,  giving  motion  to  the 
bevelled  cog-wheel  c.  Another  wheel  f,  placed  upon  a 
vertical  shaft,  is  made  to  revolve  by  the  motion  of  the 


TAN. 


115 


Fig.  3, 


iinM'nrrMiii 


wheel  c,  and  the  cogs  upon  its  periphery  move  the  ham- 
mer for  beating  the  bark,  and  also  the  choppers,  in  the 
second  story  of  the  building. 

D  (Fig.  4) .  A  horizontal  wheel  bevelled  upon  its  inclined 
surface,  and  toothed  in  an  epicycloidal  manner  upon  its 


Fig.  4. 


periphery.  This  wheel  turns  upon  the  upper  part  of  the 
large  horizontal  shaft  e,  which  passes  through  the  first 
floor  of  the  building.  F.  Cog-wheel,  before  referred  to, 
gearing  with  the  large  bevelled  wheel  c. 

G.  Pinion  upon  the  axle  of  the  millstone  i  (Fig.  5). 

p.  The  beam  or  handle  of  the  cutting-blades,  moving 


116 


TAN. 


upon  a  pivot^  and  made  to  rise  or  fall,  by  the  motion 
communicated  to  the  lever  by  the  cogs  upon  the  wheel 
C.  When  one  of  the  cogs  becomes  disengaged  from  the 
end  of  the  lever,  the  beam  falls  by  its  own  weight, 
and  the  steel  blades  upon  its  extremity  come  in  contact 
with  and  divide  the  pieces  of  bark  placed  between  them 
and  similar  knives  fastened  to  the  platform  at  i.  The 
platform  i  is  made  of  strong  timbers  firmly  secured  by 
bolts  to  the  rafters  of  the  floor,  so  as  to  enable  it  to 
resist  the  shock  of  the  falling  beam.  The  intervals  be- 
tween the  knife-blades  are  open,  so  that  the  divided 
pieces  of  bark  may  fall  through  them  into  a  conduit  Q, 
from  which  they  enter  the  hopper  of  the  mill  h,  to  be 
conducted  to  the  latter  by  a  guide  J  (Fig.  5).  The  lower 
part  of  the  conduit  Q  is  provided  with  a  wire-cloth,  which 


Fig.  5. 


TAN. 


117 


allows  the  powder  to  fall  into  a  box  k.  The  tan,  ground 
in  the  mill,  passes  through  the  conduit  o,  and  falls  upon 
the  sieve  or  bolter  l,  its  finer  particles  passing  through 
into  the  trough  M ;  those  which  have  not  been  sufficiently 
exposed  to  trituration  being  received  upon  the  concave 
mortar  or  support  s,  and  there  reduced  to  a  state  of  fine 
division,  by  the  action  of  the  round-headed  hammer  r, 
which  is  worked  by  the  cogs  upon  the  wheel  c.  The 
support  is  hollowed  out  in  such  a  way  that,  at  each 
blow  of  the  hammer,  the  particles  of  tan  acted  upon  are 
thrown  out  upon  the  side  opposite  to  that  at  which  they 
entered  it. 

T.  Bevelled  pinion,  in  gear  with  the  upper  surface  of 
the  wheel  d,  and  having  the  end  of  its  shaft  connected 
with  the  crank  v,  by  means  of  which  the  motion  is  com- 
municated to  the  machinery  for  fleshing  the  skins.  The 
crank  is  connected  by  means  of  the  rod  w  with  the  lever 
X,  the  end  of  which  is  perforated  with  a  number  of  holes, 
by  which  the  bar  is  so  adjusted  that  the  length  of  the 
stroke  may  be  increased  or  diminished. 

y  (Fig.  3) .  Shaft  moving  upon  two  axles,  the  sockets  of 
which  are  imbedded  in  the  opposite  walls  of  the  room ;  the 
lever  y  (Fig.  4)  is  connected  with  it  near  one  end ;  and  at 
about  two-thirds  of  its  length  the  cranks  n,  are  attached, 
which  give  a  reciprocating  movement  to  the  branches  A,  A, 
which  support  the  fleshing-knives ;  so  that,  at  each  revo- 
lution of  the  crank  v,  to  admit  the  movement  of  which 
there  is  an  opening  in  the  ceiling  above  it,  the  branches 
h,  ^,  for  fleshing  the  skins,  are  made  to  move  in  a  trans- 
verse direction.  In  Fig.  4,  the  knife  for  fleshing  is  repre- 
sented at /,  fixed  between  two  springs  a,  a,  which  render  it 
sufficiently  movable  to  prevent  it  from  injuring  the  skins 
when  passing  across  them.    It  is  fastened  by  its  forked 


118 


TAN, 


extremity  to  the  branch  hhy  a  screw  and  nut,  so  that  it 
can  be  unscrewed  and  sharpened  when  necessary. 

z.  Stop  on  the  branch  h,  which  is  connected  with  the 
forked  lever  e,  by  means  of  which  the  knife  is  made  to 
return  to  the  end  of  the  skin  without  touching  its  surface. 
The  extremity  of  the  branch  h  rolls  upon  the  roller  I, 
By  lowering  the  handle  m,  the  knife  is  elevated,  while' 
the  skin  is  being  placed  upon  or  removed  from  the  table. 
h.  Table  or  bench  upon  which  the  skins  are  deposited. 
Each  table  is  provided  with  four  wheels  p,  running  in 
the  grooves  g,  which  maintain  it  in  position,  and 
enable  it  to  be  moved  at  will  by  the  levers  c,  c,  so  that 
each  portion  of  skin  may  be  in  turn  subjected  to  the 
action  of  the  knife. 

d,  A  spring,  pressing  upon  the  skin  near  the  edge  of 
the  table,  so  as  to  prevent  it  from  changing  its  position 
under  the  fleshing-knife.  The  iron  support,  or  handle  of 
the  knife,  is  forked  or  divided,  so  as  to  receive  the  blade 
between  its  two  extremities.  The  knife  is  12  or  13 
inches  in  length,  and  from  3  to  5  inches  in  breadth,  and 
is  adjusted  in  the  open  part  of  the  handle,  being  pre- 
vented from  swerving  by  the  two  springs  %  a. 

The  roller  Z,  with  its  forked  lever,  should  be  so  ar- 
ranged that  the  knife  can  be  elevated  to  the  proper  dis- 
tance from  the  table,  by  pulling  the  handle  m,  and  hook- 
ing it  upon  a  nail,  so  that  the  skin  may  be  removed  or 
placed  upon  the  table  without  the  necessity  of  ungearing 
the  pinion  t  ;  the  work  being  again  commenced  when  the 
handle  is  allowed  to  rise. 

Two  benches  or  tables  are  used  in  this  apparatus,  in 
order  that  the  knife  may  be  in  operation  above  one  of 
them,  while  the  workman  is  occupied  in  adjusting  a  fresh 
skin  upon  the  other.  These  benches  should  be  as  wide 
as  the  largest  skins,  and  should  be  made  sloping  at  a 


TAN. 


119 


slight  angle.  The  skins  are  kept  in  close  contact  with 
the  surface  of  the  support,  by  clamps  pressing  their  bor- 
ders down  upon  its  edges.  The  pressure  of  the  knives 
upon  the  skin  is  regulated  by  weights  placed  upon  the 
beams  or  branches  which  support  them.  The  inventor 
does  not  confine  the  application  of  this  portion  of  the 
machinery  to  the  preparation  of  skins  for  the  tanning 
process;  but  also  adapts  it  to  the  purposes  of  tawing  and 
to  those  of  the  currier,  by  substituting  hard  brushes  or 
other  implements  for  the  knives.  Motion  may  be  com- 
municated to  the  machinery  by  the  water-wheel  already 
described,  by  a  steam-engine,  or  by  horse  power;  the 
labor  of  two  horses  being  sufficient  for  the  purpose. 

Weldoris  Mill  for  Grinding  Oah-Bark. — Fig.  6,  A, 
Wooden  beam  or  cross-piece,  imbedded  in  the  walls  of 


0 

•  % 

Q 

the  building,  and  perforated  for  the  reception  of  the  upper 
axle  of  the  main  shaft. 

B.  Iron  plate  or  socket  for  the  axle. 

c.  Axle  of  the  shaft,  the  dotted  lines  showing  its 
connection  with  the  latter. 


120 


TAN. 


D.  The  shaft,  which  may  be  square,  octagonal,  or  of 
other  suitable  form. 

E.  Lever  giving  motion  to  the  shaft  by  the  power  of 
horses,  harnessed  to  the  end.  When  water  or  other 
power  is  employed,  the  lever  is  replaced  by  a  wheel  with 
the  proper  gearing. 

F.  Cylinder  forming  the  lower  part  of  the  mill.  It 
should  be  made  of  iron  or  brass,  and  may  be  either  com- 
pact or  hollow,  as  shown  by  the  dotted  lines  in  the  figure, 

G.  Teeth,  or  projections  for  breaking  and  grinding  the 
bark. 

H.  Lower  teeth  for  the  same  purpose. 

I.  External  iron  or  brass  cylinder,  provided  with  simi- 
lar projections  upon  its  inner  surface,  and  firmly  clamped 
and  bolted  to  the  solid  framework  Q,  which  forms  the 
base  of  the  machine. 

K.  Lower  pivot  or  axle,  firmly  united  with  the  main 
shaft,  and  turning  in  a  socket  like  the  upper  one. 

L.  Iron  or  copper  socket,  fixed  in  the  cross-beam  r. 

M.  Eegulating  screw  passing  through  the  nut  n,  and 
the  lower  cross-beam  t.  By  turning  it,  the  teeth  within 
the  mill  may  be  made  to  approach  or  recede  from  each 
other,  so  as  to  effect,  at  will,  a  coarser  or  finer  division  of 
the  bark. 

0.  Hopper,  made  of  strong  wood,  for  receiving  the 
materials  which  are  to  be  ground. 

p.  Conical  lining  of  the  interior  of  the  mill,  also  made 
of  strong  wood.  The  whole  apparatus  is  supported  upon 
four  uprights  Q,  Q,  firmly  imbedded  in  the  ground,  and  ^ 
held  together  by  the  cross-beams  r  and  t,  there  being 
two  at  R,  meeting  each  other  at  right  angles.  Sieves  of 
wire  are  placed  between  the  cylinder  f  and  the  floor, 
which  permit  the  passage  through  their  interstices  of  the 
fine  tan,  and  retain  that  which  is  too  coarse. 


TAN. 


121 


Since  its  first  introduction,  Mr.  Weldon  has  improved 
the  construction  of  his  mill,  by  making  the  teeth  mova- 
ble, and  by  other  changes  which  we  proceed  to  describe. 

Fig.  7.  Section  of  the  improved  mill. 


A,  A.  Hopper  for  receiving  the  bark. 

B.  Shaft  of  the  mill. 

c.  Conical  casing  of  the  cutting  surfaces,  for  feeding 
the  mill. 

D,  D.  Collar  for  staying  the  teeth,  with  four  bolts,  h. 

E.  Elevation  of  the  conical  part  of  the  mill  in  which 
the  teeth  are  placed. 

G.  Section  of  the  opposite  side,  showing  the  manner 
in  which  the  teeth  are  adjusted. 

d,  d.  One  of  the  teeth  entering  the  lower  neck. 

H,  H.  Lower  collar  in  which  the  teeth  are  imbedded, 
a,  a,  a.  Outer  cylinder,  or  cone,  cast  in  one  piece,  and 


Fig.  7. 


9 


122 


TAN. 


showing  the  manner  in  which  the  movable  teeth  f, 
are  adjusted. 

I,  I.  Rim  or  collar  for  the  attachment  of  the  movable 
teeth;  a  part  of  it  is  seen,  detached,  in  Fig.  8. 

K,  K.  Support  of  the  interior  of  the  mill,  fastened  to 
the  outer  cone  or  cylinder  by  two  bolts  c,  c. 


Fig.  8.  Fig.  9. 


L.  Lower  part  of  the  shaft,  turning  in  a  copper  socket 
M,  which  rests  upon  the  top  of  a  screw  by  which  the 
height  of  the  inner  part  of  the  mill  is  regulated.  Fig.  9 
exhibits  this  part,  with  the  collar  of  the  rim,  in  which 
the  socket  and  adjusting  screw  are  placed. 

Fig.  10.  One  of  the  movable  teeth,  detached  from  the 
exterior  of  the  mill. 

Fig.  11  is  one  of  the  teeth  from  the 
interior  of  the  mill. 

These  teeth  are  blades  of  iron  or 
composition-metal,  ground  to  an  edge,  and  so  placed  in 
the  mill  that  the  cutting  surfaces  are  opposed  to  each 
other,  and  inclined  in  a  direction  opposite  to  that  of  the 
revolution  of  the  shaft. 

Farcofs  Bark- CJiopping  Machine. — This  machine  con- 
sists of  two  feeding  cylinders  A,  A  (Fig.  12),  which  con- 
vey the  bark,  previously  spread  out  upon  an  inclined 
table  a,  to  the  edges  of  four  large  steel  blades  b  b,  which 
are  fixed  in  a  spiral  direction  upon  the  periphery  of  two 
parallel  circles,  revolving  with  the  shaft  c.  The  cylin- 
ders A,  A,  are  grooved,  and  are  moved  by  cog-wheels  with 


Fig.  10. 


TAir.  123 

Fig.  12. 


long  teeth.  The  power,  from  whatever  source,  is  trans- 
mitted at  the  same  time  to  these  wheels  and  to  the 
bladed  circles ;  5  is  a  steel  tie-piece  which  supports  the 
pieces  of  bark  when  exposed  to  the  action  of  the  knives, 
each  of  the  latter  passing  over  it,  like  one  blade  of  a 
pair  of  shears  over  the  other. 

The  levers  f  suspend  the  weight  G,  the  object  of  which 
is  to  bear  upon  the  shaft  of  the  cylinder  A,  which  is  con- 
stantly elevated  by  the  passage  of  the  bark  beneath  it. 
Guides  are  so  placed  as  to  direct  these  levers  in  their 
vertical  movements,  and  the  bark  is  prevented,  by  guards 
or  side  pieces,  from  falling  out  of  the  grooves,  over  the 
sides  of  the  cylinders.  The  feeding  c^dinders  are  2  feet 
2  inches  in  circumference,  and  the  relation  of  the  pinion 
of  the  wheel  c  to  the  wheel  J  which  moves  it,  is  that  of 
1  to  5.  About  56  feet  of  bark  will  pass  between  the 
cylinders  in  one  minute;  in  the  same  time  the  wheel 
makes  130  revolutions,  and  as  it  is  armed  with  4  blades, 
the  bark  is  cut  into  520  pieces,  each  one  nearly  li^oth 
inches  in  length.  More  than  1600  pounds  of  bark  can 
be  chopped  in  an  hour  with  this  machine,  when  in  good 


124  TAN. 

order  and  properly  worked.    Some  are  made,  with  which 
one  man  can  work  up  daily  more  than  3000  pounds. 
Fig.  13  is  the  plan  in  elevation. 


Fig.  13. 


Fig.  14  is  the  ground  plan. 


Fig.  14. 


I 

TAN. 


125 


Fig.  15  shows  the  axle-pin  of  the  bladed  cyHnder;  and 


Fig.  16  is  an  end  view  of  the  latter. 


Fis.  15. 


Fiff.  16. 


Fig.  17  represents  the  cast-iron  frame  which  supports 
the  channelled  cylinders  and  bladed  cylinder. 


Fig.  17. 


The  bark,  after  being  chopped  as  described  above,  is 
submitted  to  the  action  of  the  mill,  which  consists  chiefly 
of  two  parts,  the  receiving  and  the  revolving  cylinder. 
The  former  is  a  thin,  hollow  cylinder,  terminated  below 
by  a  truncated  cone,  the  interior  of  which  is  provided 
with  spiral  blades  or  teeth,  some  of  which  extend  as  far 
as  the  lower  part  of  the  cylinder.  The  base  of  the  cone 
is  attached  by  legs  to  the  cast  framework  which  supports 
the  whole  apparatus.  Above  the  cylinder  is  a  hopper, 
which  is  fed  from  time  to  time  with  chopped  bark,  the 
powdered  tan  falling  down  between  the  outer  cylinder 
and  the  inner  one.    The  outer  surface  of  the  movable 


126 


TAN. 


cylinder  is  provided  with  spiral  teeth,  similar  to  those  of 
the  inner  one,  and  made  of  a  wedge-shape,  so  as  to  pre- 
sent a  cutting  edge  to  the  fragments  of  bark,  which  are 
first  cut  and  divided  by  the  teeth  which  extend  towards 
its  upper  part,  and  are  then  pulverized  by  those  upon 
the  two  conical  surfaces.  The  cylinder  is  made  to  re- 
volve by  a  shaft  set  in  a  socket  which  is  stayed  by  a 
tie-piece.  This  latter  is  traversed  by  a  screw,  by  means 
of  which  the  nut  may  be  raised  or  lowered,  so  as  to  in- 
crease or  diminish  the  space  between  it  and  the  receiving 
cylinder,  and  to  alter  at  will  the  quality  of  the  powder 
as  to  fineness  of  division.  A  bar  passes  horizontally 
across  the  interior  of  the  inner  cylinder,  and  is  firmly 
attached  to  the  shaft  passing  through  it.  The  horse 
moving  the  machinery  is  harnessed  to  an  arm  attached 
to  a  cast-iron  plate  on  top  of  the  shaft.  This  mill  is 
calculated  to  make  25  revolutions  in  a  minute,  and  is 
capable  of  grinding  8600  pounds  of  bark  in  24  hours. 

Bourgeois  s  Bark  Mill, — This  machine,  which  was  in- 
vented in  1841,  and  is  described  in  volume  liv.  page 
193,  of  the  French  reports  of  expired  patents,  is  used  to 
grind  bark  by  means  of  two  cylinders,  one  of  which 
(Figs.  18  and  19),  serving  as  a  case  for  the  handle,  is  of 
a  cylindrical  shape  externally,  while  the  other  and  in- 
ternal one  is  conical;  the  mill  revolving  in  a  vertical 
instead  of  a  horizontal  direction.  The  outer  cylinder 
12  is  fixed  by  an  iron  framework,  10,  to  the  wooden  sup- 
ports of  the  mill,  while  the  inner  cylinder,  11,  is  mova- 
ble. This  cylinder  and  the  inner  surface  of  the  outer 
one,  are  both  fluted  with  longitudinal  grooves,  describ- 
ing curves  along  their  length.  Each  of  these  grooves  is 
divided  into  two,  at  the  larger  end  of  the  cylinder,  and 
into  four  at  the  smaller  end,  the  separation  commencing 
at  the  middle.    The  inner  cylinder  can  be  completely 


TAN". 


127 


encased  in  the  outer  one,  by  the  turning  of  the  screws, 
14,  and  the  arrangement  of  grooves  is  intended  to  effect 
a  more  or  less  complete  division  of  the  particles  of  tan. 

When  the  cylinders  are  closely  in  contact,  the  bark  is 
first  exposed  to  the  action  of  the  larger  grooves,  which 
are  deeper  than  the  others,  and  then  becomes  engaged  in 
the  second  and  third  divisions,  by  means  of  which  it  is 
reduced  to  a  finer  powder.  If  it  be  desired  to  produce  a 
less  complete  trituration,  the  screws,  14,  are  loosened,  and 
the  spring,  13,  then  presses  the  inner  cylinder  from  its 
place,  in  such  a  manner  that  the  bark  is  only  acted  upon 
by  the  larger  grooves. 


Fig.  18. 


Fig.  18.     1.  Hopper  of  the  mill. 

2.  Spout  of  the  hopper. 

3.  Regulator  of  the  spout. 

4.  5.  Escapement  wheel. 

6.  Handle  of  the  regulator. 


128 


TAN, 


7.  his,  strap  attached  to  the  spout. 
8;,  9,  10.  The  spout  and  its  motive  appli- 
ances— spring  and  strap. 

11.  Handle  for  turning  the  machine. 

12.  Arm  of  the  lever  turning  the  spout. 

13.  Trundle. 

14.  Large  cog-wheel. 

15.  Small  cog-wheel. 

16.  Internal  conical  cylinder. 

17.  External  conical  cylinder. 

18.  Trough  for  receiving  the  tan. 

19.  Wooden  framework. 

Fig.  19. 


i 

s 

\3  1 

ly 

\0  8 

\ 

J]Ili!=== 

Y 

=4 

7 

m 

7 

^&=( 

W 

Fig.  19.     1.  Fly-wheel. 

2.  Spout  under  the  hopper. 

3.  Hopper. 

4.  Trundle. 

5.  Lever  arm  for  turning  the  spout. 

6.  Axle  of  the  lever. 

7.  8,  9.  The  motor  and  regulating  appli- 

*  ances  of  the  spout. 
10.  Framework  supporting  the  cylinders. 


TAN. 


129 


11.  Internal  cylinder,  with  grooves  cut  as 

before  described. 

12.  External  cylinder  channelled  like  the 

inner  one. 

13.  Spring,  regulating  the  inner  cylinder. 

14.  15.  Compressing  screws,  acting  upon  this 

cylinder. 

16.  Spring  acting  upon  the  spout, 

17.  Escapement  wheel. 

18.  Regulator  of  the  spout. 

19.  Handle  of  the  regulator. 

20.  Axis  of  the  cylinders. 

21.  Small  canting-wheel. 

22.  Large  canting-wheel. 

23.  Axle  of  the  trundle  and  fly-wheel. 

24.  Crank. 

25.  Wooden  framework, 

Lespinasses  Bark  Mill. — This  apparatus  was  invented 
in  1843,  and  is  described  in  vol.  lix.  at  page  428,  of 
the  French  expired  patent  reports.  Fig.  20,  <i,  iron 
shaft  turned  by  the  pinion,  moved  by  the  power,  and 
supporting  and  moving  the  stops  of  the  rammers  or 
stampers,  c,  shown  at  h  in  the  figure.  This  shaft  acts 
upon  the  conical  pinion,  e,  and  through  it  upon  the  simi- 
lar vertical  pinion,/,  which  communicates  the  motion  to 
a  small  horizontal  shaft,  upon  which  there  is  another 
similar  pinion,  ^,  by  means  of  which  the  horizontal 
pinion,  ^,  is  made  to  revolve.  This  latter  transmits 
the  motion  to  a  vertical  shaft,  o,  and  gives  a  recip- 
rocating movement  by  means  of  the  pinions,  /,  h,  to 
the  curb,  placed  horizontally  between  the  sides  of  the 
rammer,  n.  This  curb,  by  its  constant  movement  to  and 
fro,  forces  the  portions  of  bark  divided  by  the  knives  of 


130 


TAN. 


Fig.  20. 


the  rammer,  7^,  through  the  holes,  made  of  different  di- 
mensions in  the  sides  of  the  apparatus,  into  the  conduit, 
and  the  trough,  u.  Above  this  latter,  is  a  drum,  con- 
nected by  a  strap,  5,  to  which  the  buckets,  6,  are  adapted, 
with  a  similar  drum,  2'.  These  two  drums  are  made  to 
revolve  by  a  strap,  moving  at  one  end  over  a  drum,  7, 
placed  at  the  extremity  of  the  shaft,  dj  and  at  the  other, 
upon  another  drum,  7',  above  the  preceding,  and  which 
is  connected  with  that  supporting  the  strap,  5,  with  the 
buckets,  so  that  these  latter,  in  their  revolution,  become 
filled  with  the  tan  in  the  trough,  Uy  and  empty  it  into 
the  wooden  hopper,  8. 


TAN. 


131 


In  the  bottom  of  this  hopper  is  an  opening  connected 
"with  a  wooden  conduit,  leading  to  a  sieve,  which  is  di- 
vided lengthwise  into  three  parts,  each  of  which  is  per- 
forated with  holes  of  different  sizes.  This  sieve  is  moved 
by  an  arrangement  below  it,  which  is  connected  with  the 
strap,  y. 

12.  Troughs  to  receive  the  residue  from  the  sieve,  10. 

13.  Bags  in  which  the  residue  of  tan  is  placed. 

14.  Cords  keeping  the  bags  in  place  under  the  mouth 
of  the  trough. 

15.  Lever  of  the  rammers. 

i.  Arched  framework  for  keeping  the  shaft,  o,  in  a  verti- 
cal position.  This  shaft  is  divided  into  two  parts,  con- 
nected by  means  of  a  coupling,  <s,  which  may  be  separated 
at  will,  by  means  of  an  iron  tool,  attached  to  the  frame- 
work of  the  machine. 

1.  Small  stops  for  regulating  the  movement  of  the 
rammers. 

2.  Cushions  through  which  the  arms  of  the  curb  pass. 

3.  Framework  supporting  the  horizontal  shaft,  ?. 

4.  Supports  of  the  drums,  over  which  the  buckets  re- 
volve. 

a.  Wooden  framework  of  the  machine. 
h.  Beam  supporting  the  pegs  for  keeping  the  rammers 
at  rest. 

c.  Rammers  with  knives  at  their  lower  ends. 

16.  Cross-bars  made  to  revolve  by  the  shaft,  o,  so  as  to 
strike  against  the  wooden  box,  ^,  and  hasten  the  descent 
of  the  tan  into  the  trough. 

Wiltses  Mill, — This  machine,  known  as  the  "Catskill 
Mill,"  and  extensively  used  in  the  tanneries  of  the  United 
States,  is  made  by  A.  and  B.  Wiltse,  intelligent  and  enter- 
prising machinists  of  Catskill,  Green  Co.,  New  York. 
It  is  constructed  upon  the  principle  of  the  shears,  the 


132 


TAN". 


teeth  being  arranged  with  their  edges  at  an  angle,  and 
thrown  forward,  so  that  the  bark  may  be  driven  in  and 
ground  rapidly,  and  passed  through  without  interruption. 
Fig.  21  represents  the  machine,  which  may  be  driven  by 


water  or  steampower,  and  so  arranged  as  to  receive  the 
bark  from  the  breaker  and  to  deliver  it  ground  in  the 
leach-vats.  To  give  a  better  idea  of  the  manner  in  which 
it  works,  we  give,  on  page  133,  a  plan  showing  the  rela- 
tive positions  of  the  breaker,  bark-mill,  and  leach-vat. 
Fig.  22  is  drawn  upon  a  scale  of  a  quarter  of  an  inch  to 
one  foot. 

A  is  the  water-wheel,  and  G  its  shaft;  B  is  the  bevel- 
wheel  which  drives  the  bevel  pinion  D  on  the  foot  of  the 
main  upright  which  also  carries  a  spur-wheel  and 
drives  a  spur-pinion  F  on  the  shaft  G.  The  top  of  the 
mill  sets  ten  inches  below  the  second  floor,  in  order  to 
admit  the  bark  running  from  the  cracker  /,  K,  above. 
This  latter  consists  of  a  cast-iron  curb  or  hoop  e/",  of  18 
inches  diameter,  and  ten  inches  depth,  with  three  jagged 
teeth,  as  shown  in  end  and  interior  views  at/.  The  top 
of  the  cracker  K  is  made  of  two  blocks  of  wood,  firmly 
secured  to  two  uprights,  represented  by  the  dotted  lines, 


Fig.  21. 


134 


TAN. 


by  means  of  bolts  passing  through  the  portion  which  laps 
them.  The  two  blocks  of  K  have  openings  in  their  cen- 
treSj  of  18  inches  diameter  at  the  base,  and  24  inches  at 
the  top,  to  correspond  with  the  size  of  the  curb  on  which 
they  rest.  About  7i  inches  from  the  bottom  are  four 
strong  wrought-iron  teeth,  so  inserted  as  to  be  in  the 
centre  between  the  teeth  on  r.  The  latter  are  secured  to 
the  shaft  ^  inside  of  as  indicated  by  dotted  lines ;  and 
/S,  5,  is  also  similarly  placed  on  shaft  X,  inside  of  j.  A 
second  length  of  the  iron  shaft  X,  drives  N  by  the  aid  of 
the  bevel-wheels  M  and  which  are  so  geared  as  to 
drive,  in  turn,  the  pulley-shaft  0  at  the  head  of  the  ele- 
vators. The  elevators  take  the  bark  from  the  mill  and 
deliver  it  into  a  bark-room  or  loft  above  the  leach-tubs 
whence  it  may  be  drawn,  as  wanted,  through  a  trap. 

The  drawing  shows  two  leach-tubs,  but  the  number  may 
be  increased  according  to  the  demands  of  the  tannery. 

The  above  mill  possesses  superior  advantages,  as  it 
does  its  work  effectually  and  with  despatch.  It  cuts  the 
fibre  of  the  bark  short,  without  flouring  it,  and  passes 
it,  even  when  wet,  without  becoming  clogged.  It  is  de- 
signed, also,  for  purposes  of  economy  and  durability,  as 
well  as  of  convenience;  the  arrangements  of  the  parts 
being  such,  that  when  any  of  them,  by  wear,  require  re- 
newal, they  may  be  easily  removed  and  replaced  by 
others. 

When  worked  to  its  utmost  capacity,  it  will  grind  from 
one  to  two  cords  of  bark  per  hour,  and  must  be  driven 
at  the  rate  of  150  revolutions  per  minute  by  a  ten-horse 
engine.  At  100  revolutions  it  is  less  efficient.  With 
one  horse  power,  it  may  be  driven  at  the  rate  of  five 
revolutions  per  minute,  and  will  then  grind  one  cord  in 
from  one  to  three  hours.  The  cracker  should  move  at 
the  rate  of  30  to  40  revolutions  per  minute. 


TAN. 


135 


If  steam  is  used  as  the  propelling  force,  the  waste 
steam  may  be  economized  and  applied  to  heating  the 
leach-vats.  A  convenient  arrangement  for  this  purpose 
is  constructed  by  the  Messrs.  Wiltse. 

Birelys  Mill. — Another  ingenious  grinding  apparatus 
is  that  invented  by  Mr.  Valentine  Birely,  of  Frederick 
County,  Maryland.  It  reduces  the  bark  to  shreds  and 
strings,  forms  favorable  to  the  entire  extraction  of  its 
soluble  matter  by  the  liquor  of  the  vats.    Fig.  23  pre- 

Fig.  23. 


sents  a  perspective  view,  and  Fig.  24  a  vertical  cross- 
section  of  the  machine. 

The  framework  is  of  cast-iron,  with  apertures  at  the 
sides  for  the  journals  of  three  cylinders,  and  flanges  and 
ribs  for  securing  a  wooden  hopper.  These  cylinders  are  * 
of  different  diameters,  and  are  propelled  by  means  of  a 
drum  and  cogs  at  the  ends.  Being  denticulated  on  their 
surfaces,  and  revolving  in  concaves  similarly  studded 
with  teeth,  and  arranged  in  alternate  order  to  correspond 
with  the  reversed  movements  of  the  cylinders,  the  bark 


136  TAN. 

Fig.  24. 


is  reduced  with  great  readiness,  and  the  mill  runs  with- 
out obstruction.  The  coarse  teeth  of  the  first  cylinder 
break  it  down  preparatory  to  its  passage  through  the 
next,  and  finally  the  last  cylinder,  which  delivers  it 
ground  to  the  required  degree  of  fineness. 

These  mills  are  made  of  three  sizes,  and  the  largest, 
driven  by  a  ten-horse  power  engine  at  the  rate  of  80 
revolutions  per  minute,  will  turn  out  twenty-five  cords  of 
bark  every  twelve  hours. 

The  lengths  of  the  cylinders  in  the  three  different 
sizes  are,  respectively,  21,  24,  and  33  inches;  and  the 
smaller  ones  grind  in  proportion  to  the  power  applied. 


CHAPTER  XI. 
THE  STRUCTURE  AND  CONSTITUTION  OF  SKIN. 

The  tegumentary  membranes  encase  the  whole  surface 
of  the  body,  and  are  prolonged  into  its  interior,  so  as  to 
line  its  various  cavities  and  passages.  These  internal 
prolongations,  however,  are  called  mucous  membranes, 
and  differ  in  character  from  the  external  integument  or 
shin,  of  which  alone  it  is  our  intention  to  treat. 

The  skin,  or  dermoid  tissue,  presents  the  same  form 
and  extent  as  the  body  which  it  covers,  and  follows  all 
its  inequalities  of  surface.  It  is  corrugated  in  many 
places  into  wrinkles  or  plaits,  on  account  of  its  not  being 
susceptible  of  the  same  degree  of  expansion  and  con- 
traction as  the  more  mobile  tissues  which  it  envelops; 
the  largest  wrinkles  being  produced  by  the  contractions 
of  muscles  and  the  flexion  of  joints.  The  outer  surface  of 
the  skin  is  comparatively  smooth  and  uniform  ;  is  covered 
more  or  less  with  the  secretions  from  bulbs  or  follicles 
which  are  called  hair,  or  wool,  and  also  presents  numerous 
papillary  projections  and  minute  depressions,  which  latter 
are  the  orifices  of  the  perspiratory  and  sebaceous  ducts, 
proceeding  from  glands  or  follicles,  in  which  the  secre- 
tions destined  to  moisten  the  surface  are  eliminated.  The 
inner  surface  of  the  skin  is  connected  with  and  tied  to  the 
subjacent  parts  by  an  areolar  or  cellular  tissue,  which 
binds  them  together  more  or  less  tightly,  in  proportion 
10 


138  THE  STRUCTURE  AND 

to  the  less  or  greater  freedom  of  motion  of  which  the 
skin  is  capable.  This  cellular  tissue  contains  in  its  cavi- 
ties adipose  or  fatty  matter,  which  confers  the  requisite 
firmness  and  solidity  upon  the  parts,  and  protects  the 
structures  beneath  the  skin  from  the  injurious  effects  of 
undue  pressure.  The  cellular  tissue  is  also  penetrated  in 
various  directions  by  the  bloodvessels  and  nerves  distri- 
buted upon  the  skin,  and  in  some  instances,  gives  passage 
to,  and  supports  cutaneous  muscles,  which  are  inserted 
directly  into  its  base. 

The  skin  is  a  compound  membrane,  and  though  actu- 
ally consisting  of  only  two  distinct  tissues,  may  be  con- 
veniently divided,  as  has  been  the  habit  of  most  anato- 
mists, into  three  layers,  viz. ;  corium,  rete  mucosum,  and 
cuticle. 

The  Corium,— The  corium,  cutis  vera,  or  true  skin, 
forms  the  basis  or  principal  part  of  the  skin,  being  much 
thicker  than  the  other  layers,  and  giving  them  support. 
It  consists  of  a  cellulo-fibrous  tissue,  which  upon  macera- 
tion, appears  to  be  made  up  of  dense  filaments,  crossing 
each  other  in  various  directions,  so  as  to  inclose  spaces 
or  areolae.  These  are  of  considerable  size  at  the  inner 
surface  of  the  membrane,  where  granules  of  fat,  blood- 
vessels, and  nerves  project  into  them,  but  diminish  to- 
wards the  outer  surface,  where  the  structure  becomes 
dense  and  uniform.  This  latter  is  not  perfectly  smooth, 
but  is  studded  with  minute  prominences  called  papillaSy 
which  project  in  many  places  so  much  as  to  be  evident 
to  the  sight  and  touch,  and  which  have  been  supposed 
by  some  anatomists  to  constitute  a  separate  layer,  called 
textus  'papillaris.  The  tactile  sensibility  is  believed  to 
depend  upon  its  degree  of  development. 

The  corium  is  generally  white,  owing  any  changes  of 
color  to  the  greater  or  less  amount  of  blood  present  in  it. 


CONSTITUTION  OF  THE  SKIN. 


139 


It  is  supple  and  elastic.  When  dried,  it  presents  the 
appearance  and  properties  of  horn,  and  is  converted  into 
gelatine  by  boiling  in  water. 

The  Rete  Mucosum. — The  next  layer  of  the  skin,  the 
rete  mucosum,  is  a  soft  gelatinous  tissue,  spread  out  upon 
the  surface  of  the  corium,  between  it  and  the  cuticle. 
The  composition  of  this  stratum  has  given  rise  to  much 
discussion.  It  appears  to  be  a  semi-fluid  deposit  or  se- 
cretion, rather  than  an  organized  substance,  although 
Gautier  and  other  anatomists  have  not  merely  admitted 
its  existence  as  a  separate  element  of  the  skin,  but  have 
resolved  it  into  four  distinct  layers,  placed  one  over  the 
other.  In  white  skins,  it  is  without  color,  and  so  thin 
that  it  is  difficult  even  to  demonstrate  it.  It  is  the  seat 
of  the  pigmentum^  or  coloring  matter,  which  darkens  the 
skins  of  the  colored  races  of  men  and  of  some  animals, 
and  in  them  is  very  evident.  This  coloring  material  is 
disseminated  throughout  its  substance,  in  the  form  of 
minute  globules,  Avhich  are  supposed  to  consist  chiefly  of 
carbon.  The  rete  mucosum  is  now  believed  to  consist 
of  granules,  forming  the  deepest  and  most  recently  depo- 
sited portion  of  the  cuticle,  not  compressed  into  scales 
or  laminse,  like  the  more  superficial  particles. 

The  Cuticle. — The  cuticle,  epidermis,  or  scarf-skin,  is 
the  outer  or  superficial  layer  of  the  integument,  and  is 
connected  firmly  with  the  subjacent  tissues  by  numerous 
delicate  filaments,  and  by  the  ducts  and  hairs  to  which 
it  gives  passage;  but  it  can  be  readily  separated  from 
them  by  decoction  or  maceration.  It  is  usually  a  thin, 
varnish-like  covering  to  the  subjacent  tissues,  but  its 
thickness  varies  with  the  amount  of  pressure  to  which 
it  is  subjected.  It  is  now  acknowledged  to  consist  of  the 
same  granules  which  constitute  the  substance  of  the  rete 
mucosum,  compressed  and  hardened  into  minute  horny 


140 


COMPOSITION  OF  THE  SKIN. 


scales,  which  are  constantly  being  shed;  their  places 
being  supplied  by  new  particles  from  the  moist  and  more 
recently  deposited  granules  below  them.  The  cuticular 
surface  descends  into,  and  lines  the  follicles  which  secrete 
the  hair,  and  the  ducts  for  the  discharge  of  the  perspira- 
tory and  lubricating  fluids. 

COMPOSITION  OF  THE  SKIN. 

Having  treated  of  the  structure  of  the  skin,  we  pro- 
ceed naturally  to  consider  its  composition.  The  skin  of 
animals  consists  of  fibrine,  gelatine,  and  small  portions 
of  albumen  and  fatty  matter.  The  first  two  form,  as  it 
were,  the  basis  or  network  of  the  whole  tissue,  a  portion 
of  which,  if  boiled  with  water,  yields  its  gelatine,  while 
the  fibrine  remains.  The  epidermis  of  the  skin  does  not 
combine  with  tannin.  The  properties  of  these  substances 
which  play  such  an  important  part  in  tanning,  are  as 
follows : — 

Fibiiyie. — This  is  one  of  the  immediate  and  most 
abundant  principles  in  animals.  It  exists  in  the  chyle 
and  blood,  and  is  the  basis  of  muscle.  It  may  be  pre- 
pared by  whipping  blood  with  a  bunch  of  twigs,  and 
washing  the  coagulum  of  fibrous  filaments  in  fresh  water 
until  it  loses  color.  It  is  a  white,  tasteless,  inodorous 
solid,  heavier  than  water,  soft,  slightly  elastic,  and  with- 
out action  upon  litmus.  Fibrine  loses  four-fifths  of  its 
weight  by  drying,  and  becomes  yellowish,  hard,  and 
brittle,  but  regains  much  of  its  original  appearance  by 
soaking  in  water.  It  is  insoluble  in  cold  water,  and 
hardens  without  dissolving  in  hot  water,  but  is  modified 
in  composition  and  properties.  When  left  in  contact 
with  cold  water,  for  several  days,  decomposition  accom- 
panied by  a  cheesy  odor,  ensues. 


COMPOSITION  OF  THE  SKIN. 


141 


With  weak  caustic  \yes  of  soda  and  potassa,  it  first 
gelatinizes  and  then  forms  yellow  solutions  at  from  120° 
to  130°  F.  If  the  lyes  are  concentrated,  ammonia  is 
given  off  during  the  heating.  Caustic  ammonia  is  less 
feeble  in  its  action  than  the  fixed  alkalies. 

These  alkaline  solutions  are  precipitated  by  several 
metallic  salts,  with  the  oxides  of  which  it  forms  impu- 
trescible  compounds;  for  example,  with  the  chloride  of 
mercury  and  sulphates  of  copper  and  iron.  The  same 
reactions  ensue  when  fibrine  is  digested  in  solutions  of 
metallic  salts. 

Dilute  sulphuric  acid  shrivels  fresh  fibrine,  and  ulti- 
mately combines  with  it,  forming  a  jelly  soluble  in  water. 
Dry  fibrine  is  changed  by  strong  acid  into  a  yellow, 
gelatinous  mass,  without  being  dissolved.  In  large  quan- 
tities, the  reaction  evolves  heat,  develops  sulphurous 
acid,  and  blackens  the  mass. 

Nitric  acid  generates  nitrogen  and  new  derivatives  of 
fibrine.  Hydrochloric  acid  forms  a  blue  solution,  from 
which  water  precipitates  white  hydrochlorate  of  fibrine. 
If  the  acid  be  very  dilute,  the  fibrine  swells  and  becomes 
gelatinous.  Concentrated  acetic  acid  rapidly  gelatinizes 
fibrine,  and  renders  it  soluble  in  hot  water. 

Tannin  precipitates  it  from  both  its  acid  and  alkaline 
solutions,  and  when  fresh  fibrine  is  immersed  in  solution 
of  tannin,  it  becomes,  on  drying,  tough,  hard,  and  impu- 
trescible. 

Its  ultimate  percentage  composition,  according  to 
Dumas  and  Cahours,  is : — 

Carbon   52.78 

Hydrogen      .       .       .       .       .  6.96 

Oxygen,  &c.  (sulphur  and  phosphorus)  23.48 

Nitrogen   16.78 


100.00 


142 


COMPOSITION  OF  THE  SKIN. 


Gelatine. — CisHioOs^Ng.  This  is  an  immediate  animal 
principle,  and  derives  its  name  from  the  fact  of  its  hot 
aqueous  solution  forming  a  transparent,  tremulous  jelly 
on  cooling.  It  is  found  in  bones,  horns,  muscles,  tendons, 
and  ligaments,  although  it  does  not  pre-exist  as  such  in 
these  tissues ;  and  it  may  be  prepared  by  the  prolonged 
action  of  boiling  water  upon  them. 

Isinglass,  size,  and  glue  are  different  kinds  of  gelatine, 
varying  in  physical  properties  according  to  their  source. 
The  gelatine  from  cartilage  is  named  Ghondrine,  and  pos- 
sesses properties  different  from  those  of  true  gelatine  or 
glutin,  as  it  is  termed  by  way  of  distinction. 

Glutin  is  the  principal  component  of  glue,  and  is  pre- 
pared in  a  pure  state,  by  soaking  the  latter  repeatedly  in 
quantities  of  fresh  water,  until  all  soluble  matters  are 
removed,  and  by  then  boiling  and  straining  the  residue. 

Gelatine  is  colorless,  or  yellowish,  transparent,  taste- 
less, and  inodorous.  It  does  not  lose  its  transparency 
by  drying,  but  becomes  hard,  brittle,  and  horny.  It 
softens  and  swells,  and  very  slightly  dissolves  in  cold 
water,  but  is  very  soluble  in  hot  water,  from  which  alco- 
hol precipitates  it.  Repeated  and  successive  boilings 
and  coolings  of  its  aqueous  solution  impair  its  gelatin- 
izing property. 

By  immersion  in  alcohol,  it  loses  water  and  shrinks. 
It  is  soluble  in  all  the  dilute  acids  and  in  caustic  alka- 
line lyes,  and  therefore  its  aqueous  solution  is  not  dis- 
turbed by  either.  Chlorine  gas,  however,  produces  in  it 
white,  elastic  flocculae.  Gelatine  is  not  altered  by  boiling 
with  hydrated  lime. 

Subacetate  of  lead  precipitates  aqueous  solutions  of 
gelatine,  as  also  do  the  sulphate  of  platinum,  nitrates  of 
mercury,  protochloride  of  tin,  and  (by  boiling)  neutral 
persulphate  of  iron. 


COMPOSITION  OF  THE  SKIN. 


143 


Alcohol  and  ether  are  without  action  upon  dry  gela- 
tine. 

The  characteristic  property  of  gelatine  is  that  of  com- 
bining with  tannin,  and  forming  a  grayish,  glutinous, 
elastic  compound,  which,  upon  drying,  becomes  unalter- 
able and  imputrescible  in  water,  and  forms  the  basis  of 
leather. 

The  mutual  affinity  of  these  two  substances  is  so  strong 
that  the  latter  will  precipitate  the  former  from  a  solution 
containing  so  little  as  one  part  in  5000  parts  of  water. 
Gelatine,  however,  does  not  exist  exactly  as  such  in 
skins,  and  therefore  leather  (a  compound  of  gelatinous 
tissue  and  tannin),  though  very  analogous  to,  is  not 
strictly  identical  with  this  elastic  precipitate  of  tanno- 
gelatine,  which  is  slightly  soluble  in  water  and  becom.es 
brittle  on  drying. 

Mulder,  who  has  examined  the  subject,  says  that  there 
are  two  definite  compounds  of  tannin  with  gelatine.  For 
example,  when  a  solution  of  pure  gelatine  is  mixed  with 
one  containing  a  great  excess  of  tannin,  the  resulting 
precipitate,  which  is  white  and  curdy,  and  becomes  red- 
dish-brown, hard  and  brittle  on  drying,  consists  of  one 
equivalent  of  tannic  acid  and  one  of  gelatine.  This  is 
the  neutral  compound.  If,  however,  the  tannin  be  not 
added  in  excess,  then  the  compound  will  contain  three 
equivalents  of  gelatine  and  two  of  tannic  acid.  The  pre- 
cipitate of  gelatine  by  infusion  of  oak  bark  is  composed, 
according  to  Davy,  of  54  parts  of  gelatine  and  46  of 
tannin;  or  100  of  the  former  and  85.2  of  the  latter. 
Schiebel  found  that  100  parts  of  gelatine  in  solution, 
when  precipitated  by  a  great  excess  of  infusion  of  oak 
bark,  made  with  1  part  of  bark  to  9  of  water,  com- 
bines with  118.5  parts  of  tannin.  If,  how^ever,  the  in- 
fusion be  weak,  and  not  added  in  sufficient  quantity  to 


144 


COMPOSITION  OF  THE  SKIN. 


precipitate  the  whole  of  the  gelatine,  the  compound 
which  is  thrown  down  and  slowly  subsides,  consists  of 
100  gelatine,  and  only  59.25  of  tannin. 
The  ultimate  composition  of  gelatine  is 


Lowig. 

Mulder. 

Carbon 

.  50.00 

50.04 

Hydrogen  . 

.  6.41 

6.47 

Oxygen 

.  25.64 

25.13 

Nitrogen 

.  17.95 

18.36 

100.00 

100.00 

Albumen  is  a  component  of  nearly  all  the  animal 
solids ;  and  when  free  from  foreign  matters,  is  soluble  in 
water.  This  solution  coagulates  at  160°  F.;  but  the 
coagulum  may  be  re-dissolved  by  heating  it  with  water 
in  a  digester  to  400°  F. 

As  precipitated  from  the  aqueous  solution  of  white  of 
eggs,  or  of  the  serum  of  blood,  it  is  pure  and  soluble  in 
acetic  acid,  very  weak  alkalies,  and  in  soluble  salts  with 
alkaline  bases.  Its  solution  in  nitrate  of  potassa  is  co- 
agulable  by  boiling. 

Albuminous  solutions  are  precipitated  by  sulphuric 
acid.  Hydrochloric  acid  produces  a  coagulum  soluble 
in  water,  and  in  strong  hydrochloric  acid  by  heat.  Ni- 
tric acid  throws  down  a  flocculent  precipitate,  soluble  in 
alkalies,  even  from  very  dilute  solutions.  Acetic  acid 
gives  no  precipitate,  even  by  heat,  unless  both  acid  and 
solution  are  concentrated.  In  that  case,  a  gelatinous 
compound,  soluble  in  excess  of  acid,  and  in  water,  is 
formed. 

Albumen  is  soluble  in  alkalies.  Waters  of  lime,  baryta, 
and  strontia,  have  no  reaction  upon  the  aqueous  solution 
of  albumen ;  but  with  the  alkaline  earths  themselves  it 


COMPOSITION  OF  THE  SKIN. 


145 


forms  insoluble  compounds.  Earthy  and  metallic  salts 
throw  down  double  compounds,  one  with  acid  and  another 
with  metallic  oxide,  the  latter  of  which  is  wholly  insolu- 
ble, while  the  former  is  not  entirely  so. 

Tannin  precipitates  albuminous  solutions,  but  the  re- 
sulting compound  is  not  softened  by  heat  like  the  tanno- 
gelatine. 

According  to  Weinholt,  fresh  skin,  freed  on  its  internal 
side  from  fat  and  cellular  tissue,  and  on  its  grain  side 
from  the  epidermis  and  mucous  membrane,  contains  42 
per  cent,  of  solid  matter,  and  58  of  water.  The  solid 
matter  consists  of 

Cellular  tissue   32. 

Albumen  ......  1.50 

Extractive  matter  (soluble  in  water 

and  in  alcohol)      .       .       .       .  1.00 

Extractive  (soluble  in  water,  but  in- 
soluble in  alcohol)        .       .       .  7.50 


42.00 


CHAPTEE  XII. 


OF  THE  DIFFERENT  KINDS  OF  SKINS  SUITABLE  FOR 

TANNINa. 

Skins  are  technically  classified :  1.  As  hides,  which 
comprise  the  skins  of  oxen,  horses,  cows,  bulls,  and  buf- 
fliloes,  and  are  employed  for  thick  sole  leather.  2.  As 
hips,  consisting  of  the  skins  of  the  younger  growth  of 
the  above  animals,  and  3.  As  sldns,  of  small  animals  such 
as  dogs,  sheep,  goats,  seals,  &c.,  which  are  used  for  upper, 
thin,  and  fancy  leathers. 

The  quality  of  leather  depends  not  only  upon  the  na- 
ture of  the  skin  and  the  mode  of  tanning  it,  but  upon 
the  results  of  numerous  minor  details  which  require 
especial  care  and  attention. 

Hides  or  skins  retain  their  original  name  until  after 
they  have  been  subjected  to  treatment  in  the  lime-pit. 
When  placed  in  the  tan-vats,  they  become  leather. 

Hides  are  sent  to  market  either  fresh  from  the  slaugh- 
ter-house; or  dried,  or  salted;  or  both  dried  and  salted. 

Besides  the  skins  furnished  from  the  slaughter-houses, 
our  tanners  work  large  supplies  imported  from  Buenos 
Ayres,  Brazil,  Texas,  and  California.  They  also  obtain 
small  lots  of  stock  from  the  Antilles,  west  coast  of  Africa, 
and  from  other  parts  of  the  world.  Those  of  Russia  are 
larger  and  stronger  than  either  the  French  or  our  own ; 
but  we  receive  very  few  of  them  in  their  raw  state,  nearly 
all  being  imported  already  tanned  into  leather. 


SKINS  SUITABLE  FOR  TANNING. 


147 


Some  supplies  are  likewise  drawn  from  the  Levant, 
and  from  the  Spanish  possessions  in  America.  Sheep- 
skins are  imported  from  the  Cape  of  Good  Hope,  and 
Buenos  Ayres;  goat-skins  from  Barbary;  lamb  and  kid 
skins  from  Italy;  and  seal-skins  from  Newfoundland. 
Kips  come  from  Buenos  Ayres,  St.  Petersburg,  and  the 
East  Indies.  The  supply  of  domestic  hides  is  compara- 
tively limited.  Swiss  hides  are  of  excellent  quality,  but 
we  get  few  or  none  of  them  in  this  country. 

Skins  from  large  cattle  are  best,  provided  they  are  not 
thin  and  flabby,  for  such  will  only  make  inferior  leather. 
Those  from  cattle  slaughtered  in  the  colder  months,  give, 
it  is  said,  five  per  cent,  more  leather  than  hides  taken  in 
summer.  The  nature  of  the  food  and  state  of  the  ani- 
mal's health,  also,  have  an  influence  upon  the  quality  of 
the  hide. 

For  the  production  of  40  pounds  of  leather,  there  are 
required,  as  the  average,  30  pounds  of  dry  hide,  60 
pounds  of  salted  hide,  or  74  pounds  of  market  hide. 

Those  from  Brazil  and  Buenos  Ayres,  whence  our  stock 
of  foreign  hides  is  principally  drawn,  are  of  sufiicient  good- 
ness for  tanning  if  they  have  not  undergone  any  injury 
during  the  importation.  Sometimes,  however,  the  process 
by  which  they  have  been  dried,  renders  them  brittle  and 
only  serviceable  for  conversion  into  glue. 

The  Buenos  Ayres  hides  are  taken  from  the  wild  cattle 
which  are  run  down  by  hunters.  After  being  removed 
from  the  carcass,  they  are  spread  upon  the  ground  with 
the  flesh  side  uppermost,  and  left  exposed  to  sun  and  air 
until  dry.  To  prevent  shrinking  and  wrinkling,  the  hides 
are  kept  stretched,  by  means  of  wooden  pegs  driven 
through  the  corners  into  the  earth. 

Brazilian  hides  are  nearly  all  slaughtered  in  the  ordi- 
nary manner. 


148 


SKINS  SUITABLE  FOR  TANNING. 


It  would  be  greatly  to  the  interest  of  the  tanner,  and 
would  save  him  much  annoyance,  if  all  hides  were  im- 
ported in  a  green  state,  that  is,  merely  salted ;  for  when 
dry,  it  is  very  difficult,  even  for  the  most  experienced, 
to  detect  many  defects  which  would  impair  the  quality 
of  the  leather  into  which  it  is  to  be  converted. 

The  large  ox-hides  are  the  ones  chiefly  used  for  con- 
version into  sole  leather;  for  cow-skins,  though  of  denser 
structure,  are  rather  too  thin  for  this  purpose,  and  are, 
therefore,  reserved  for  making  saddler's  leather.  This 
latter  remark,  however,  applies  only  to  the  hides  of  old 
cows  which  have  repeatedly  calved.  These  are  weak 
and  distended.  The  hides  of  heifers,  on  the  contrary, 
are  considered  equal,  if  not  superior  to  those  of  oxen. 

Bull-hides,  on  the  other  hand,  are  the  least  esteemed 
of  all,  being  thinner,  and  more  flabby  than  those  of  either 
oxen  or  cows. 

A  well-fed,  moderately-worked  ox,  when  slaughtered 
in  a  healthy  condition,  will  naturally  yield  a  hide  of 
normal  quality.  But  if  sick,  lean,  or  deficient  in  hair  at 
the  time  of  being  killed,  then  the  hide  is  not  adapted  for 
making  good  leather.  Should  the  animal  die  suddenly 
by  accident,  without  any  diseased  condition,  the  quality 
of  the  hide  is  not  thereby  impaired.  The  hides  from  un- 
healthy bullocks  or  horses,  present  a  decided  difference 
from  those  of  the  same  animals  slaughtered  in  a  sound 
condition.  This  difierence  is  not  distinguishable  by  any 
very  evident  characters,  though  it  seldom  escapes  the 
sagacity  of  an  experienced  tanner. 

There  are  no  definite  rules  for  estimating  the  quality 
of  hides.  If  a  skin  is  free  from  the  defects  already  men- 
tioned, and  has  sufficient  strength  and  thickness,  with 
body  and  firmness,  then  it  may  be  presumed  that  it  will 
tan  well,  and  make  good  leather.   A  skin  presenting  the 


SKINS  SUITABLE  FOR  TANNING. 


149 


opposite  characters,  that  is  flabby,  soft,  thin,  loeak,  and 
will  not  bear  handling,  should  not  be  considered  reliable. 
These  signs,  however,  are  not  always  unerring,  for  ano- 
malous cases  frequently  occur.  Indeed,  it  may  sometimes 
happen  that  the  hides  from  a  diseased  carcass,  differing  in 
appearance  from  the  rest,  will  produce  excellent  leather. 

As  the  skins  could  not  be  kept  any  length  of  time  in 
a  fresh  state  without  being  injured  by  putrefaction; 
and  as  it  would  be  impossible  to  transfer  them  as  soon 
as  slaughtered  to  the  tan-vats,  they  are  preserved  un- 
altered by  salting  or  drying  them.  The  country  butchers 
stretch  them  out  in  drying-lofts  or  in  the  shade;  while 
those  in  the  city  generally  salt  them.  Steger,  a  Hunga- 
rian tanner,  recommends  the  application  with  a  brush  of 
a  coating  of  pyroligneous  acid,  which  he  says  will  not 
only  preserve  the  hides,  but  even  arrest  incipient  putre- 
faction without  impairing  their  good  quality  in  other  re- 
spects. 

The  skins  from  the  slaughter-houses  in  cities  or  towns, 
and  their  environs,  are  generally  sold  to  the  tanners 
soon  after  being  stripped  from  the  carcass,  and  in  a  green 
state.  Although  it  is  the  usual  custom  to  salt  hides,  it 
is  never  done  by  the  butcher  when  the  transfer  to  the 
tannery  is  to  be  immediate.  Those  butchers  who  live 
at  a  distance,  have  necessarily  to  salt,  or  else  to  dry 
them,  so  as  to  preserve  them  in  a  marketable  condition, 
during  their  storage  and  transportation. 

In  the  sale  of  unsalted  green  hides,  there  are  certain 
reprehensible  frauds  which  it  is  diflicult  to  provide 
against.  For  instance,  not  only  are  the  horns,  ears,  and 
other  less  valuable  parts  left  upon  the  skin,  but  the 
butcher,  in  order  still  further  to  increase  its  weight,  beds 
the  animal,  before  slaughtering  it,  in  filth  and  mire,  and 


150 


SKINS  SUITABLE  FOR  TANNING. 


then,  after  skinning  it^  trails  the  hide  upon  the  dusty 
ground. 

Domestic,  or  Slaughter  Hides, — Heavy  hides  are  con- 
verted into  sole,  belt,  and  harness  leather.  The  very 
largest  are  selected  for  carriage-tops.  The  smaller  and 
lighter  ones  are  used  for  "skirting"  and  for  enamelling. 
When  intended  for  ladies'  shoes,  or  bridle-leather,  they 
undergo  a  bleaching  process,  in  the  currier's  shop,  termed 
"  fair  finish."  The  hides  from  northern  latitudes  are 
preferable  to  those  from  the  South.  Hides  from  the 
extreme  South  are  particularly  objectionable  for  conver- 
sion into  leather.  Those  from  California,  when  free 
from  the  defects  caused  by  unskilful  skinning,  are  of 
good  quality. 

Spanish,  or  South  American  Hides. — The  dry  hides  are 
generally  converted  into  sole  leather,  and  occasionally 
into  belt  leather.  Those  imported  in  the  green  and  salt 
states,  are  sometimes  made  into  upper  leather,  which  is 
of  fair  quality. 

African  hides  from  the  west  coast  make  good  uppers; 
but  are  largely  used  in  their  raw  state  for  covering  hair 
trunks.  Madagascar  hides  are  good  when  perfect,  which 
is  rarely  the  case,  as  they  are  liable  to  injury  during 
curing  or  transit. 

Calf-sMns, — The  hides  of  the  neat  yearlings  go  into 
calf-skins.  Of  these  latter,  there  are  "  Patna"  kips  and 
common  calf  for  bookbinders.  The  Patna  kips  are  very 
inferior,  and  though  frequently  sold  as  "  Calcutta"  kips, 
have  the  distinctive  property  of  greater  weight.  A  few 
kips  come  from  South  America,  and  some  from  England 
and  Ireland.  The  supplies  of  the  tanneries  are  mostly 
domestic  skins. 

Calf-skins  are  valued  in  proportion  to  their  strength 


SKINS  SUITABLE  FOR  TANNING.  151 

and  size.  The  French  tanners,  who  are  renowned  for 
the  excellence  of  their  calf  leather,  use  the  skins  taken 
from  animals  of  five  or  six  months  of  age.  Those  from 
calves  of  less  than  two  months'  age  are  very  inferior, 
and  only  suitable  for  the  manufacture  of  parchment. 

Buffalo  Hides. — Those  from  our  plains  are  prepared 
with  the  hair  on,  by  the  American  Indians,  as  robes. 
The  so-called  buffalo  hides,  imported  from  the  East  In- 
dies, are  tanned  into  sole  leather  of  inferior  quality. 
Prepared  in  a  particular  manner,  with  oil,  they  become 
buff  belt"  leather.  An  inferior  "  buff  belt"  leather  is 
also  made  from  cow-hides. 

Horse  Hides  are  tanned  for  uppers  and  make  good 
leather.  They  are  also  tanned  for  thongs  for  sewing 
belts,  &c.,  and  are  the  best  material  for  that  purpose. 

Goat-skins,  when  tanned  and  curried,  are  used  for  the 
uppers  of  ladies'  shoes.  Tanned  in  a  particular  manner, 
and  dyed  with  fancy  colors,  they  constitute  Morocco  or 
Turkey  leather.  By  tawing,  they  are  converted  into 
Chamois,  or  wash  leather,  which  is  also  made  from  deer- 
skins. The  best  goat-skins  come  from  Mexico,  and  are 
known  in  commerce  as  "  Tampico"  skins.  The  sound 
skins  from  the  Cape  of  Good  Hope  are  very  large  and 
far  superior  to  those  from  Madras  and  the  Cape  de 
Verds. 

Sheep-shins  make  a  spongy  weak  leather,  used  prin- 
cipally for  linings  and  trunk  trimmings.  Saddlers  and 
bookbinders  also  use  them  largely.  When  curried  and 
blackened,  they  may  serve  as  inferior  upper  leather  for 
children's  shoes.  Sheep-skins  are  also  converted  into 
parchment  and  vellum. 

Hog-shins  are  tanned  exclusively  for  saddle  seats. 

Dog-shins  make  good  leather.  They  are  also  tawed 
for  glovers'  use. 


152 


MODE  OF  SALTING  HIDES. 


Beaver  and  hucTc  shins  are  mostly  tawed  or  oiled  for 
glovers'  use. 

Ass  or  mule  shins  serve  to  make  shagreen  or  sagri  for 
the  manufacture  of  scabbards. 

Seal-shins  are  converted  into  materials  for  caps  and  fur 
clothing.  Many  are  also  tanned  into  upper  leather  of 
inferior  quality.  The  large  skins  come  from  the  Falk- 
y  land  Islands,  and  the  small  ones  from  Newfoundland. 

White  porpoise-shins. — Porpoise  leather,  properly  tan- 
ned, is  said  to  be  strong,  soft,  and  of  beautiful  finish.  It 
is  made  in  Canada. 

Leather  is  differently  designated  in  commerce,  accord- 
ing to  the  mode  in  which  it  is  curried  or  dressed,  and 
sometimes  the  use  for  which  it  is  intended.  For  exam- 
ple, "harness"  leather  is  blackened  in  the  grain;  "  russet" 
is  "  fair  finished"  leather;  wax  leather  is  blackened  in  the 
flesh;  and  "bufi*"  is  that  with  the  grain  divided  by  care- 
ful shaving  and  blackened  on  the  grain  side. 

MODE  OF  SALTING  HIDES. 

Delalande's  method,  which  is  that  generally  adopted, 
consists  in  laying  open  the  hides  upon  the  ground,  and 
sprinkling  the  flesh  sides  with  salt,  more  liberally  at  the 
edges  and  on  the  spinal  portions,  than  on  other  parts. 
They  are  then  folded,  or  doubled  lengthwise,  down  the 
centre.  The  remaining  folds  are  made  over  each  other, 
commencing  with  the  shanks,  then  the  peak  of  the  belly 
upon  the  back,  afterwards  the  head  upon  the  tail  part, 
and  tail  part  upon  the  head,  and  lastly,  by  doubling  the 
whole  with  a  final  fold,  and  forming  a  square  of  one  or 
two  feet.  This  being  done,  they  are  then  piled  three 
and  three  together,  and  left  until  the  salt  has  dissolved 
and  penetrated  their  tissue,  which  generally  requires 


MODE  OF  SALTING  HIDES. 


153 


three  or  four  days.  Thus  prepared,  they  are  sent  to 
market. 

Skms  may  be  dried,  even  after  having  been  salted,  by 
stretching  them  upon  poles,  with  the  flesh  sides  upper- 
most, and  exposing  them  to  dry  air  in  a  shady  place. 

Ten  pounds  of  salt  in  summer,  and  somewhat  less  in 
winter,  are  requisite  for  each  skin  of  ordinary  size. 


11 


CHAPTER  XIII. 


PRELIMINARY  TREATMENT  OF  SKINS. 

In  order  to  prepare  the  raw  hides  for  the  action  of  the 
tanning  agent,  it  is  necessary  to  subject  them  to  several 
preliminary  operations.  These  consist  in  soahmg^  or 
washing  in  water,  and  fulling,  or  heating,  in  order  to 
soften  them,  and  to  remove  the  adhering  blood  and  filth ; 
swelling,  or  raising,  to  "plump"  the  hide;  depilating,  to 
separate  the  hair;  fleshing,  or  worJdng  on  the  beam,  to  re- 
move the  loose  flesh,  fatty  matter,  &c.,  from  the  flesh 
side,  and  the  epidermis  and  hair  from  the  grain  side ; 
and  riming. 

These  leading  manipulations  are  modified  to  suit  cer- 
tain kinds  of  skins,  as  will  be  directed  hereafter;  and 
some  undergo  an  additional  treatment,  termed  "  hating,'' 
to  remove  lime,  and  otherwise  promote  the  thorough 
union  of  the  tan  material  and  the  gelatinous  structure. 

WASHING  AND  SOAKING. 

This  is  the  first  operation  that  the  skins  must  under- 
go, and  it  is  therefore  a  great  convenience  to  have  the 
tannery  located  upon,  or  near  to  a  stream  or  running 
spring,  with  an  abundance  of  water.  The  skins  are 
taken  in  a  green,  dry,  or  salted  state. 

The  green  hides  are  those  from  recently  slaughtered 


WASHING  AND  SOAKING. 


155 


animals.  They  are  placed  in  water,  and  left  to  soak  for 
half  a  day,  or  longer,  if  necessary,  for  the  removal  of 
blood  and  adhering  dirt.  If  the  skins  are  not  very  dirty, 
an  hour  is  sufficient.  They  are  to  be  well  rinsed  before 
taking  them  out  of  soak.  If  it  should  be  necessary  to 
soak  them  for  a  longer  time,  they  must  be  handled  or 
moved  about  at  frequent  intervals. 

If  the  water  is  abundant  and  the  current  rapid,  time 
and  trouble  will  be  saved  by  planting  stakes,  or  a  kind 
of  rack  across  the  stream,  and  so  fastening  the  skins 
thereto  that  the  friction  of  the  water  may  loosen  the  dirt 
and  carry  it  off.  Care  should  be  taken  to  suspend  the 
skins  so  that  they  may  not  be  damaged  by  rubbing 
against  the  stones  at  the  bottom  of  the  stream. 

Dry  skins  necessarily  require  a  longer  soaking;  and  to 
facilitate  the  operation,  it  is  necessary  to  remove  them 
from  the  water  frequently,  and  each  time  to  stretch  them, 
beat  them  under  feet,  and  work  them  upon  the  wooden 
horse,  as  shown  in  Fig.  25,  with  the  fleshing-knife.  Fig. 
26,  and  then  leave  them  to  drain.    The  fleshing  should 


Fig.  25. 


be  repeated  once  or  twice.    This  manipu-        Fig.  26. 
lation  softens,  cleanses,  and  stretches  the  ^^^^^ 
hide. 

The  working  and  scraping  must  be  continued  until  all 
the  slimy  and  other  animal  matters  which  are  prone  to 


156 


WASHING  AND  SOAKING. 


putrefaction  are  removed.  No  definite  length  of  time 
can  be  prescribed  for  the  soaking  of  the  skins;  they  are 
to  remain  in  the  water  until  they  have  become  supple, 
and  the  intelligence  of  the  workman  must  determine 
when  this  point  is  attained.  If  the  soaking  should  be  too 
prolonged,  the  skins  will  acquire  a  tendency  to  putrefy. 
It  need  hardly  be  mentioned  that  skins  which  have  been 
salted  and  dried,  require  a  longer  soaking  than  those  that 
have  only  been  dried. 

The  working  and  softening  of  the  hides  upon  the  horse, 
or  beam,  are  considered  indispensable  operations  by  all 
experienced  tanners,  though  there  are  some  who  omit 
them. 

When  the  skins  have  been  all  soaked  and  washed,  as 
above  directed,  and  are  sufficiently  supple,  they  are  re- 
turned to,  and  left  in  the  water  for  five  or  six  hours.  In 
a  fresh  running  stream  they  may  remain  as  long  as  eight ; 
but  in  still  water  not  more  than  five  or  six  hours.  Re- 
ference is  here  made  exclusively  to  the  large  hides;  for 
cow-skins  may  be  left  without  danger  of  injury,  for 
twenty-four,  and  calf-skins  forty-eight  hours ;  some  atten- 
tion being  always  given  to  the  nature  of  the  water  and 
temperature  of  the  atmosphere.  It  must  be  remembered 
that  a  too  long-continued  soaking  in  the  same  water  ex- 
poses the  skins  to  the  danger  of  putrefiiction ;  and  the 
rapidity  of  this  decomposition  is  proportional  to  the 
amount  of  filthy  foreign  matter  contained  in  the  water. 

The  skins  which  have  been  well  salted,  but  not  dried, 
may  be  cleansed  in  forty-eight  hours;  but  they  may  be 
left  to  soak,  without  injury,  for  three  or  four  days.  They 
must,  however,  be  withdrawn  once  daily,  left  to  drain  for 
two  hours,  worked  with  the  back  of  the  fleshing-knife, 
and  well  rinsed  in  water.  These  manipulations  are 
necessary  not  only  for  removing  salt  and  dirt,  but  also 


WASHING  AND  SOAKING. 


157 


for  rendering  them  soft  and  supple.  When  they  are 
taken  from  the  water  for  the  last  time,  the  rinsing  must 
be  viororous  and  thorousrh. 

At  Saint  Saens,  the  mode  of  soaking  hides  is  pecuhar 
to  that  ph^ce.  They  commonly  use  the  dry  hides  from 
South  America,  which  are  placed  directly  in  vats  filled 
with  lime-water,  and  left  for  six  or  ten  days,  care  being 
taken  to  work  them  in  the  usual  manner  at  frequent 
intervals  during  the  soaking.  These  vats  are  eight  feet 
long  and  five  feet  wide. 

The  skins  are  softened  by  the  action  of  the  lime,  and 
rendered  more  easy  to  be  handled,  and  it  is  at  this  stage 
that  the  defective  parts  may  be  detected  by  critical  ex- 
amination. Sometimes  they  are  so  damaged  as  to  be 
suitable  only  for  the  manufacture  of  glue. 

In  the  Belgian  town  of  Liege,  where  they  mostly  use 
the  dry  hides  from  Brazil  and  Caraccas,  there  is  no  allot- 
ted time  for  soaking.  They  follow  a  method  which,  though 
laborious,  prevents  an  over-soaking  of  the  hides.  After 
four  or  five  days  they  examine  each  vat,  and  withdraw 
such  hides  as  have  become  soft,  and  leave  the  rest. 
This  culling  process  is  repeated  daily,  until  all  the  hides 
have  been  withdrawn.  The  skins  which  require  the 
longest  soaking,  and  are  taken  out  the  last,  are  those 
which  have  been  damaged  by  sea-water  during  transport- 
ation. 

As  soon  as  the  hides  are  taken  from  the  vats,  they  are 
worked  upon  the  horse,  and  then  returned  to  the  water. 
On  the  following  day  they  are  thoroughly  rinsed,  and 
placed  in  the  drying- room.  The  working,  or  frotting, 
is  solely  to  remove  the  wrinkles  and  stiffness  of  the  dry 
skins.  These  manipulations  are  unnecessary  for  the 
green  hides. 

Although  some  manufacturers  contend  that  the  quality 


158 


WASHING  AND  SOAKING. 


of  the  leather  is  improved  in  proportion  to  the  duration 
of  the  soaking  of  the  skin,  it  is  still  undeniable  that, 
when  it  exceeds  a  certain  time,  the  skin  acquires  a  tend- 
ency to  decomposition,  and  the  quality  of  the  leather 
is  thus  impaired. 

Of  the  Influence  of  the  Soahing-water  upon  the  Quality 
of  the  Leather. — It  is  a  mooted  point  whether  the  nature 
of  the  water  used  for  soaking  has  any  influence  upon  the 
quality  of  the  leather.  In  the  absence  of  any  positive 
knowledge,  it  is  perhaps  better  to  take  the  affirmative  side 
of  the  question.  Dessables  says,  it  is  undeniable  that 
the  leathers  known  as  calf-skins,  and  which  by  their 
very  nature  and  destined  uses  should  be  soft  and  supple, 
require  a  soft,  fresh  water,  and  consequently  that  it  will 
be  difficult  to  make  them  with  that  which  is  hard. 

We  will  treat  this  subject  by  giving  a  chemical  view 
of  the  different  kinds  of  water. 

In  modern  chemistry  water  is  known  as  oxy-hydric  acid, 
or  protoxide  of  hydrogen.  When  pure,  it  is  inodorous, 
colorless,  transparent,  elastic,  and  strongly  refractive  of 
light,  and  a  conductor  of  heat  and  electricity.  It  is  com- 
pressible, with  disengagement  of  light,  boils  at  212°  F., 
and  freezes  at  32°  F.  Those  waters  which  are  called 
j)otahIe,  or  soft,  will  dissolve  soap,  while  those  that  do  not 
possess  this  property,  are  not  so  good  for  drinking,  and 
are  termed  hard.  The  former  are  nearly  free  from  solu- 
ble matters,  while  the  latter  contain  calcareous  and  other 
salts,  which  they  have  taken  up  in  their  transit  through 
the  soil.  The  ultimate  composition  of  absolutely  pure 
water  is  88.9  parts,  by  weight,  of  oxygen,  and  11.1  of 
hydrogen.  The  agreeable  taste  of  fresh  water  is  due  to 
the  atmospheric  air  which  it  contains;  when  this  is  ex- 
pelled by  boiling,  water  becomes  insipid. 


WASHING  AND  SOAKING. 


159 


Rain-water. — The  purest  rain-water  is  that  which  falls 
in  the  country,  or  in  sparsely  settled  localities,  where 
there  are  no  noxious  emanations.  That  which  is  first 
collected  should  not  be  retained. 

The  soluble  impurities  of  rain-water  are  those  which 
it  has  dissolved  from  the  atmosphere,  and  consist  of 
minute  traces  of  chloride  of  sodium,  carbonate  of  am- 
monia, and  carbonic  acid.  The  suspended  matters  with 
which  it  is  sometimes  charged,  are  taken  up  in  its  flow 
over  the  house-roofs.  The  rain-water  after  thunder- 
storms contains,  in  addition  to  the  above  constituents, 
small  traces  of  nitric  acid  and  of  nitrates. 

Snow-water. — According  to  Bergmann,  snow,  which  is 
crystalline  rain-water,  loses  the  gases  held  by  it,  upon 
being  melted. 

Spring  and  Fountain-water. — Rain-waters,  in  travers- 
ing earthy  strata,  gradually  collect  in  cavities,  from  which 
they  gush  to  the  surface.  It  is  evident,  therefore,  that 
water,  in  its  transit  through  the  soil,  must  become  charged 
with  such  constituents  thereof  as  are  soluble  in  it;  and 
consequently  the  purity  of  the  water  is  proportional  to 
the  insolubility  of  the  earths  through  which  it  has  flowed. 

The  purest  spring-waters  contain  air,  carbonic  acid, 
and  minute  quantities  of  hydrochlorate  and  carbonate  of 
soda. 

River-water. — River-water  does  not  differ  materially 
from  spring-water,  since  it  is  from  the  union  of  the  latter 
with  rain-water  that  it  is  formed.  Sometimes,  however, 
it  is  purer,  from  having  deposited  its  suspended  matter, 
and  also  a  part  of  that  held  in  solution,  which  generally 
happens  when  it  traverses  a  long  and  silicious  bed.  If 
it  pass  over  or  through  limestonCj  or  other  strata  con- 
taining soluble  ingredients,  it  becomes  less  pure. 


160 


WASHING  AND  SOAKING. 


Lahe-Water. — Water  of  lakes  differs  from  that  of  rivers 
only  in  being  more  highly  charged  with  the  soluble  prin- 
ciples of  the  soil  upon  which  they  rest,  a  condition  which 
is  promoted  by  their  state  of  quiescence. 

MarsJi-ivater. — This  kind  of  water  is  in  even  a  more 
permanent  state  of  stagnation  than  lake-water.  When 
its  content  of  organic  matter  is  large,  putrefaction  en- 
sues, and  a  part  passes  off  in  gaseous  form,  while  the 
remainder  subsides  as  insoluble  precipitate.  If  the  de- 
composition has  not  been  complete,  some  of  the  organic 
products  will  remain  in  solution,  and  impart  a  disagree- 
able taste. 

Well-ivater. — It  might  be  inferred  that  well-water  is 
analogous  to  that  from  fountains  and  springs;  but  it 
filters  through  the  soil  much  more  slowly,  and  remains 
stagnant  usually  at  greater  depths ;  and,  consequently,  is 
more  readily  impregnated  with  the  soluble  constituents 
of  the  soil.  Hence  it  is  that  well-water  is  generally 
hard,  because  it  contains  earthy  salts,  and  more  par- 
ticularly sulphate,  or  bicarbonate,  or  hydrochlorate  of 
lime,  which  render  soap  insoluble  in  it. 

According  to  Sennebier,  there  is  more  carbonic  acid 
in  well  than  in  spring  water. 

Well-water  from  the  vicinity  of  the  sea  has  a  brackish 
taste,  and  contains  the  same  constituents  as  sea-water, 
but  in  diminished  proportions. 

When  well-waters  are  very  hard,  the  addition  of  a 
little  alkaline  carbonate  will  decompose  the  lime-salt, 
and  render  them  potable. 

It  is  very  evident  that  rain-water  is  the  purest ;  but 
all  drinkable  waters  are  applicable  for  tanning  purposes. 
To  impart  softness  to  hard  waters,  the  French  tanners 
add  a  solution  of  pigeon  or  chicken  dung  to  the  vat,  and 


WASHING  AND  SOAKING.  161 

stir  it  in  thoroughly  by  means  of  the  implement,    ^^g-  ^7. 
Fig,  27.    The  hides  are  then  put  into  soak.  In 
some  tanneries,  instead  of  washing  the  skins  in 
the  river,  they  soak  them  in  troughs. 

Waters  containing  iron  blacken  the  hides,  and 
render  the  leather  brittle. 

In  the  Paris  tanneries,  it  is  customary  to 
purify  tlie  water  by  allowing  it  to  infiltrate 
through  spent  tan.  For  this  purpose  there  is  a 
series  of  three  vats,  charged  similarly  with  spent 
tan ;  and,  as  the  water  which  is  poured  into  the  first  vat, 
is  drawn  through  a  cock  at  the  bottom,  it  is  transferred 
to  the  second,  and,  ultimately,  to  the  third  vat.  In  this 
manner  all  kinds  of  water  may  be  rendered  available  for 
tanning.  As  thus  rectified,  it  contains  a  little  tannin 
derived  from  the  spent  tan,  which  renders  it  particularly 
adapted  for  the  early  part  of  the  tanning  operation. 

Experience  certainly  proves  the  superiority  of  some 
waters  over  others  for  tanning  purposes;  but  on  what 
particular  quality  of  the  water  this  superiority  depends, 
chemists  have  not  yet  been  able  to  determine. 

The  safest  course  is  to  prefer  those  waters  which  con- 
tain the  least  soluble  matter,  particularly  earthy  salts, 
such  as  lime  and  magnesia;  for  these  certainly  reduce 
the  tanning  power  of  the  ooze,  by  combining  with  some 
of  its  constituents. 

The  suspended  matters,  consisting  of  mud,  &c.,  as 
well  as  the  soluble  organic  matter,  which  imparts  to 
water  a  bad  taste,  may  be  removed  by  filtering  the  water 
through  clean  gravel  and  fresh  charcoal. 

If  the  lime  exists  as  bicarbonate,  it  may  be  separated 
from  the  water  by  adding  lime-water,  which  precipitates 
it  as  an  insoluble  neutral  carbonate.    Boiling  produces 


162  SWELLING^  OR  RAISING. 

the  same  result,  by  expelling  the  bi-equivalant  of  car- 
bonic acid. 

SWELLING,  OR  RAISING. 

The  second  process  to  which  hides  are  to  be  subjected 
is  termed  raising^  and  is  that  by  which  the  pores  are 
distended,  the  fibres  swollen,  and  the  hair  loosened. 
These  results  are  effected  by  means  of  alkaline  or  acid 
solutions,  and  by  fermentation.  Milk  of  lime  is  the  alka- 
line liquor  generally  employed.  Lime-water  has  been 
proposed  as  a  substitute,  but  it  is  less  permanent  in  its 
action,  and  requires  frequent  renewal  in  order  to  insure 
the  perfect  cleansing  of  the  hides. 

Swelling  hy  Lime. — This  is  the  oldest  and  most  ob- 
jectionable method.  The  lime-vats  in  which  the  hides 
are  to  be  soaked,  are  made  either  of  wood  or  mason 
work,  sunk  in  the  ground,  and  plastered  interiorly  with 
hydraulic  cement.  They  may  be  round  or  square,  and 
of  dimensions  proportional  to  the  number  of  hides  to  be 
soaked.  The  usual  size  is  five  feet  square,  and  the  same 
in  depth. 

About  a  peck  of  lime  usually  suffices  for  a  large 
hide ;  and,  accordingly,  the  number  of  skins  to  be 
treated  in  each  vat  must  determine  the  proportion  of 
lime  to  be  added.  Circumstances,  however,  may  render 
it  necessary,  sometimes,  to  increase  the  quantity.  The 
practice  adopted  in  some  factories,  of  economizing  lime 
by  partially  substituting  ashes,  lye,  or  pigeon  and  dog 
dung,  &c.,  is  a  very  reprehensible  one,  as  it  produces 
injurious  effects. 

To  make  a  fresh  vat,  quicklime  is  thrown  in,  covered 
with  water,  and  agitated  with  a  stirrer,  Fig.  28,  until  it 


\ 


SWELLING,  OR  RAISING. 


163 


has  become  slaked  and  passed  into  milk.    In  this    ^^s-  ^s. 
state  the  vat  is  left  for  some  days  j  after  which, 
it  is  ready  to  receive  the  hides. 

The  vats  are  distinguished  as  dead,  weah,  and 
live  vats.  The  dead  vat  is  that  which  has  been 
nearly  exhausted  of  its  strength;  the  weah  is 
that  which  has  only  been  used  enough  to  deprive 
it  of  a  portion  of  its  force ;  and  the  fresh  or  live 
vat,  is  that  which  has  not  yet  been  worked.  In 
the  progress  of  operations,  the  live  vat  passes 
successively  into  the  weak  and  the  dead  vat. 

The  three  vats  are  termed  the  raising  series,  Fig.  29. 


Fig.  29. 


The  raising  should  be  commenced  in  the  dead  vat,  and 
continued  in  consecutive  order  through  the  series  to  the 
live  vat.  In  some  factories  the  series  consists  of  as  many 
as  twelve  vats ;  and,  in  this  case,  there  should  be  a  gra- 
dation in  the  strength  of  the  liquors.  The  duration  of 
this  operation  varies  in  different  localities.  Some  tan- 
ners leave  the  hides  in  the  vats  for  three  months,  while 
others  soak  them  for  eighteen  months.  The  old  routi- 
nists,  according  to  Dessables,  give  the  hides  a  soaking  of 
ten,  twelve,  and  even  fifteen  months;  and  then,  when 
they  have  become  sufiiciently  softened,  transfer  them  to 
a  dead  vat  for  eight  days,  at  the  end  of  which  time  they 


164 


SWELLING,  OR  RAISING. 


are  withdrawn,  hung  up  for  eight  days,  and  again  placed 
in  the  same  vat  for  eight  more  days,  and  so  on.  These 
consecutive  operations  are  thus  continued  for  two  months, 
or  until  the  hair  can  be  readily  detached. 

The  graduation  of  the  vats  varies  in  different  localities. 
In  those  parts  of  France  where  the  series  consists  of 
twelve  vats,  the  first  two  are  dead,  the  four  following 
wealc,  and  the  last  six,fres7i  or  live  vats.  Where  the 
system  comprises  only  five,  the  first  two  are  dead,  and 
the  three  last  live  vats. 

In  Brittany,  many  tanners,  believing  that  the  hides 
are  raised  better  with  the  hair  on  than  in  pelt,  give  six 
live  vats,  and  do  not  remove  them  until  after  the  fourth 
and  even  the  fifth. 

In  Auvergne,  they  give  three  raisings  of  a  month  each, 
with  a  mixture  of  lime  and  alkaline  lye. 

We  cannot  see  the  utility  of  so  many  vats,  for  when 
the  skins  have  soaked  to  the  saturating  point,  a  con- 
tinuation of  the  treatment  is  supererogatory.  Generally 
speaking,  three  or  four  vats,  with  skilful  manipulation, 
suffice  for  any  kind  of  skins.  Delalande  contends  that 
from  ten  to  twelve  months  are  requisite  for  thorough 
soaking ;  but  the  experience  of  all  good  tanners  proves 
that  two  months  are  sufficient,  and  that  in  this  time  the 
skin  becomes  soft  and  capable  of  being  readily  cleansed 
and  freed  from  its  hair. 

According  to  Curandeau,  only  ten  or  twelve  days  are 
required  for  the  transit  of  the  hides  through  the  three 
lime-vats.  He  also  thinks  that  a  longer  time  would  be 
useless,  if  not  injurious,  and  that  the  shorter  the  soaking 
the  greater  is  the  weight  acquired  by  the  hides  in  tan- 
ning. Malepeyre  adds  that  it  is  now  established :  1st, 
that  it  is  sufficient  to  leave  the  hides  in  the  pits  for 
twenty-four  hours,  and  an  equal  length  of  time  in  stack ; 


SWELLING,  OR  RAISING. 


165 


2d,  that  this  operation  should  not  continue  for  more  than 
six  or  eight  weeks  at  farthest ;  3d,  that  three,  or  at  most 
four  good  vats  are  sufficient ;  4th,  that,  after  this  interval, 
the  hides  are  easily  cleansed;  and  when,  on  the  other 
hand,  the  treatment  is  prolonged,  the  hides  become  dry 
and  parched ;  5th,  that  after  three  or  four  pits,  the  hide 
will  have  swollen  to  the  fullest  extent;  and,  finally,  that 
independently  of  these  objections,  there  is  a  great  waste 
of  time,  lime,  and  materials,  in  the  old  method  of  steep- 
ing for  from  ten  to  fifteen  months. 

Stacking  the  hides,  is  to  pile  them  one  upon  the  other 
at  the  side  of  the  vat,  as  they  are  drawn  from  it,  and 
thus  leave  them  remaining  (in  retreat)  for  a  shorter  or 
longer  time,  before  returning  them  to  the  bath  for  an- 
other wet. 

Piling  enables  the  working  of  sixty  hides  in  a  vat  of 
capacity  for  only  thirty,  by  having  one  batch  to  take 
the  place  of  the  other  in  alternate  operations.  For  ex- 
ample, while  one  set  of  thirty  is  in  retreat,  the  other 
should  be  in  the  vats,  and  vice  versa,  so  as  to  save  time. 

The  vats  should  be  covered ;  and  as  the  skins  in  retreat 
are  liable  to  become  hard  by  exposure  to  the  sun  and  air, 
they  should  not  be  kept  in  that  state  longer  than  is 
necessary.  Covers  prevent  this  as  well  as  the  retarding 
influence  of  cold ;  for,  while  the  liquid  is  frozen  on  the 
surface,  it  is  inactive. 

At  every  handling,  that  is,  upon  each  return  of  the 
skins  to  the  vats,  or  when  new  ones  are  put  in,  an  inti- 
mate mixture  of  the  water  and  lime  at  the  bottom  should 
be  made  by  a  thorough  stirring  of  the  liquor.  At  this 
time,  a  workman  at  each  end  of  the  vat,  by  the  aid  of 
tongs  (Fig.  30),  arranges  the  hides  in  it  so  that  they  may 
lie  smoothly  and  firmly.  The  suspended  lime,  by  its 
greater  weight,  soon  subsides  upon  the  hides,  and  the 


supernatant  liquor  which  should  cover  the  hides  to  a 
depth  of  some  inches^  will  be  clear  and  transparent.  As 
the  greater  portion  of  the  lime  is  in  contact  with  the 
skins  at  the  bottom  of  the  vat,  its  action  is  more  power- 
ful upon  them  than  on  those  above,  and,  consequently, 
in  recharging  the  vat  after  stacking,  the  order  of  position 
must  be  reversed;  those  that  were  originally  placed  first, 
must  be  then  last,  and  vice  versa. 

Should  the  vat,  as  often  happens,  become  too  weak  to 
produce  the  desired  effect,  it  must  be  strengthened  by  the 
addition  of  the  quantity  of  lime  necessary  to  restore  its 
force.  The  advantage  is  thus  obtained  of  giving  the 
hides  the  benefit  of  two  vats  in  one.  This  new  addition 
of  lime  should  be  made  while  the  skins  are  out  of  the 
vat. 

For  removing  the  hair,  the  scraping-hnife  alone  must 
be  used.  This  is  a  dull-edged  instrument,  which  is  not 
liable  to  damage  the  skin  by  cutting  it,  while  it  is  all- 
efficient  in  scraping  ofi*  the  hair.  It  is  a  bad  practice  to 
use  the  slate,  or  ruhher  (Fig.  31),  which,  being  rough, 
may  scratch  and  damage  the  hide  upon 

^^Fig.  31.  .^^  grain  side. 

The  use  of  sand,  ashes,  or  other  simi- 
lar auxiliaries  for  removing  the  hair  is  very  improper, 
as  they  attach  themselves  to  the  surface  and  thus  in- 


SWELLING,  or'  RAISING. 


167 


crease  the  trouble  of  cleansing  it.  It  is  also  a  bad  prac- 
tice to  wait  until  the  completion  of  the  soaking  before 
scrajDing  off  the  hair,  because  the  lime  will,  in  time,  act 
upon  the  hair  itself. 

After  the  removal  of  the  hair,  the  skins  are  rinsed, 
and  replaced  in  the  dead  vat,  and  so  on  consecutively 
through  the  series  to  the  live  vat.  It  suffices  to  leave 
the  hides  for  fifteen  days  in  each  of  these  vats,  but  care 
must  be  taken  to  stack  and  replace  them  every  twenty- 
four  hours. 

"  The  force  of  habit,  and  perhaps  the  use  of  the  Ker- 
mes  oak  bark,"  says  Tournal,  "  causes  many  tanners  to 
persist  in  the  use  of  lime.  But  if,  in  riasing,  great  care 
is  not  taken  to  remove  every  trace  of  lime,  as  is  known 
when  the  liquor  expressed  by  the  dull  knife  employed 
for  scraping  them  on  the  beam  runs  very  limpid,  the 
minute  traces  remaining,  will,  by  abstracting  carbonic 
acid  from  the  air,  become  insoluble,  and  render  the  skin 
dry,  brittle,  and  perhaps  useless.  These  faults  are  not, 
however,  solely  attributable  to  the  carbonic  acid  of  the 
air,  but  also  to  the  formation  of  tannate  of  lime,  as  well 
as  of  the  stearate  and  oleate  of  that  base,  which  are  gene- 
rated by  the  presence  of  fatty  matters  always  existing 
in  the  hides." 

^'  The  tanners,"  says  the  same  authority,  "  who  use  the 
Kermes,  pretend  that  its  warm  nature  imparts  stiffness 
to  the  leather,  and  that  consequently  the  only  available 
mode  of  raising  is  by  means  of  lime.  They  ow^n  that 
the  sour  tan-juice  and  barley  processes  distend  the  pores 
of  the  hide  much  more  than  lime ;  and  that  the  tanning 
principle  of  the  Kermes,  having  a  tendency  to  combine 
rapidly  with  the  hide  thus  swollen,  imparts  an  unnatural 
stiffness  to  the  leather.  The  reality  of  these  assertions 
may  be  readily  determined  by  tanning  with  Kermes 


168 


SWELLING,  OK  RAISING. 


some  hides  which  have  been  raised  by  the  sour  tan-liquor 
process." 

In  quoting  these  passages  we  have  adhered  to  the 
language  of  Tournal.  We  will  add  that,  according  to 
our  experience,  the  bark  of  the  Kermes  oak  is  richer  in 
tannin  than  that  of  the  ordinary  oak,  and  that  admirable 
leather  may  be  prepared  by  tanning  with  it  skins  which 
have  been  raised  by  sour  tan-liquor. 

There  are  certain  drawbacks  to  the  liming  process, 
which  are  worthy  of  enumeration.  Firstly,  the  contact 
of  caustic  lime  alters,  more  or  less,  the  texture  of  the 
hide,  and  permits  it  to  penetrate  the  pores,  and  remain 
in  them  in  the  state  of  caustic  lime,  carbonate,  or  lime- 
soap.  The  repeated  rinsings  in  water,  and  workings, 
only  partially  remove  the  lime,  which  is  a  serious  impedi- 
ment to  perfect  tanning.  It  hinders  the  ready  penetra- 
tion of  the  tan  liquor  and  the  perfect  combination  of 
tannin  with  the  skin,  and  so  obstinately  resists  removal 
during  all  the  manipulation  that  a  portion  is  found  even 
in  the  best  leather.  When,  however,  the  latter  is  to  be 
converted  into  glazed  leather,  the  curriers  first  remove 
all  the  lime  by  a  particular  method. 

Notwithstanding  that  experience  is  so  opposed  to  the 
use  of  lime,  the  careful  and  elaborate  experiments  of  Dr. 
J.  Davy  (^Ghemist,  1850),  show  that  its  action  upon  animal 
textures  generally  is  rather  antiseptic  than  destructive. 
Its  corroding  influence  is  limited  to  the  cuticle,  hair, 
nails,  and  all  gelatinous  tissues.  These  latter  become 
soft  and  gelatinous,  owing,  doubtless,  to  a  combination 
which  they  form  with  the  lime,  for  on  analyzing  the  ash 
of  the  cuticle  thus  treated,  a  large  increase  of  its  normal 
contents  of  that  earth  was  obtained. 

The  matters  were  steeped  in  milk  of  lime,  kept  caustic 


SWELLING,  OR  RAISING. 


169 


in  close  vessels,  by  the  entire  exclusion  of  air.  After 
treatment  they  ceased  to  be  putrescent. 

The  disadvantages  of  the  use  of  lime  have  led  to  the 
substitution  of  less  objectionable  agents,  which  we  will 
proceed  to  treat  of  in  succession. 

Raising  hy  Acids. — Some  tanners  substitute  an  acid 
liquor  for  the  milk  of  lime;  for  example,  the  Tartar- 
Calmucks  use  sour  milk  for  this  purpose.  Pfeiffer  has 
proposed  the  acidulated  water  obtained  by  the  distilla- 
tion of  lime  and  peat.  Sometimes  a  little  sulphuric  acid 
is  added.  In  fine,  this  acid  in  a  dilute  state,  as  also  all 
the  vegetable  acids,  will  produce  the  same  effect.  That 
which  is  formed  by  the  fermentation  of  barley  meal,  of 
rye,  and  of  tan  bark  is  acetic  acid.  Acids  have  the 
double  advantage  of  loosening  the  hair,  and  swelling  the 
hides  at  the  same  time. 

In  some  tanneries,  the  skins  are  softened  by  sprinkling 
one-half  with  salt,  and  folding  the  other  half  over  it. 
They  are  then  piled  up  and  covered  with  straw.  Fer- 
mentation speedily  ensues;  and  they  must  be  turned 
several  times  daily,  until  they  have  attained  that  state 
in  which  they  can  easily  be  depilated.  The  same  result 
can  be  attained  without  the  use  of  salt.  They  are  to  be 
piled  upon  a  bed  of  straw  and  covered  in  like  manner. 
After  twenty-four  hours,  they  are  turned  and  then  ex- 
amined twice  daily,  so  that  the  proper  point  may  not  be 
exceeded.  In  some  tanneries,  the  hides  are  imbedded 
in  horse  manure.  In  others  they  are  covered  with  tan, 
or  some  imperfect  conductor  of  heat.  Incipient  putrefac- 
tion and  consequent  loosening  of  the  hair  may  also  be 
effected  by  suspending  the  hides,  which  have  been  left 
lying  in  a  heap  for  several  days,  in  a  close  room,  kept 
above  the  ordinary  temperature  by  a  smouldering  tan 
12 


170 


SWELLING,  OR  RAISING. 


fire.  Better  results  might  be  obtained  by  circulating  a 
current  of  steam  through  the  apartment. 

All  methods  of  fermentation  are  termed  sweating  pro 
^cesses.  But  whatever  the  process  followed,  the  skins,  as 
soon  as  the  hair  begins  to  yield  readily,  are  to  be  spread 
upon  a  wooden  horse,  and  scraped  with  a  dull-edged 
knife.  In  this  manner  the  hair  and  outer  skin  are  fleshed 
or  scraped  off.  As  the  outer  skin  is  of  a  nature  different 
from  that  of  the  hide,  and  does  not  unite  with  tannin,  it 
must  necessarily  be  removed  in  order  to  allow  the  free 
passage  of  the  tan  liquor  through  the  skin  proper,  and 
thus  facilitate  the  tanning  process. 

Depilation  hy  Steam. — In  many  tanneries,  the  depila- 
tion  by  milk  of  lime  is  superseded  by  another  method, 
w^hich  subjects  the  hides  in  heaps,  to  a  slight  putrefactive 
fermentation  in  heated  chambers.  It  is  difficult,  in  warm 
seasons,  to  control  this  fermentation;  and  sometimes  it 
is  even  necessary  to  salt  the  hides.  After  some  days, 
the  epidermis  becomes  loose  and  detached,  and  may  be 
readily  scraped  off  with  the  hair. 

Belbut,  in  Paris,  and  Robinson,  of  Delaware,  employ 
steam  as  the  heating  medium,  in  an  arched  chamber  of 
eighteen  feet  in  length,  ten  feet  in  height,  and  ten  feet  in 
breadth,  and  lined  interiorly  with  cement.  The  steam 
is  introduced  beneath  a  false  bottom  of  wood,  perforated 
with  numerous  holes,  and  serving  as  the  bed  for  the  sup- 
port of  the  hides.  As  the  steam  condenses,  it  should  be 
allowed  to  escape  through  an  opening  at  the  base  of  the 
chamber. 

The  temperature  of  the  heap  should  be  maintained  at 
between  70  and  80°  F.,  and  precaution  should  be  used 
to  keep  it  uniform,  for  it  must  be  remembered  that  the 
joint  action  of  heat  and  moisture  may  dissolve  the  gela- 
tine, and  thus  cause  the  hides  to  be  scarred  with  pits.  In 


SWELLING,  OR  RAISING. 


171 


twenty-four  hours,  the  process  is  completed,  and  the  hair 
may  be  scraped  off  in  the  usual  manner.  If  the  hair 
falls  from  the  hides  when  they  are  taken  out  of  the  heap, 
it  is  owing  to  incipient  decomposition  of  the  surface. 
Beef  hides  weighing  from  eighty  to  one  hundred  pounds 
experience  a  loss  of  from  twenty-four  to  twenty-eight 
pounds. 

Depilation  hy  Caustic  Soda. — Boudet  proposes  caustic 
soda  as  an  advantageous  substitute  for  the  milk  of  lime 
for  raising  and  depilating  hides.  The  liquid  for  the  pur- 
pose is  prepared  by  decarbonating  a  very  dilute  solution 
of  soda  ash  with  a  sufficient  quantity  of  milk  of  lime, 
allowing  repose,  and  decanting  the  clear  supernatant 
caustic  soda-lye  by  means  of  a  syphon.  The  hides  im- 
mersed in  this  liquor  swell  out  rapidly  and  considerably, 
and  are  ready  to  be  scraped  in  two  or  three  days.  More- 
over, the  alkali  forming  soluble  soap  with  the  fatty  por- 
tions, facilitates  the  cleansing,  and  produces  a  smoother 
grained  side  than  is  common.  Hides  thus  prepared  are 
said  to  imbibe  the  tan  liquor  more  rapidly  than  those 
which  have  been  treated  with  lime,  to  undergo  the  entire 
process  of  tanning  in  one-third  of  the  time,  and  to  suffer 
less  loss  than  those  prepared  by  the  usual  process.  Forty- 
four  pounds  of  sal  soda  dissolved  in  132  gallons  of  water, 
and  mixed  with  33  pounds  of  slaked  lime,  suffice  for 
steeping  2200  pounds  of  fresh  hides. 

Depilation  hy  SulpJiurets  of  Gahium  and  Soda, — Bou- 
det, in  trying  the  old  method  of  depilating  by  means  of 
a  mixed  paste  of  orpiment  (sulphuret  of  arsenic),  and 
caustic  lime,  observed  that  the  arsenic  was  without  any 
direct  influence  upon  the  hair,  and  that  the  depilatory 
action  was  due  to  sulphuret  of  calcium  in  its  nascent  state, 
formed  by  the  reaction  of  the  lime  upon  the  sulphuret 


172 


SWELLING,  OR  RAISING. 


of  arsenic.  Acting  upon  this  observation,  he  replaced 
the  orpiment  by  sulphuret  of  calcium,  which,  when  made 
into  paste  with  lime,  acted  so  promptly,  that,  after  24  or 
36  hours'  contact,  the  skins  were  completely  depilated. 
The  lime  alone  has  no  depilating  effect,  and  the  sulphuret 
of  sodium  only  a  partial  action.  This  principle  was 
originally  announced  by  Martins,  and  first  applied  to 
tanning  purposes,  in  1840,  by  Boetger. 

This  mode  of  preparing  the  hides  is  said  to  render 
them  highly  susceptible  of  being  quickly  tanned.  Ex- 
perience has  yet  to  decide  what  influence  it  has  upon 
the  leather.  The  prejudice  of  tanners,  so  far,  is  against 
this  method,  which,  it  is  said,  surcharges  the  leather  with 
an  amount  of  water  that  escapes  by  evaporation  during 
storing,  to  the  great  loss  of  the  dealer ;  but  we  do  not 
think  that  this  objection  is  tenable. 

The  vat  formed  of  a  mixture  of  potash,  lime,  and 
orpiment  (sulphuret  of  arsenic),  as  proposed  by  Abram 
and  Coste,  of  Marseilles,  is  much  less  convenient  than 
the  preceding,  and  is  liable  to  numerous  objections ;  not 
the  least  of  which  is  the  danger  to  be  apprehended  in 
manipulating  with  a  liquor  containing  such  a  poisonous 
ingredient  as  orpiment. 

The  hydrosulphuret  of  calcium  is  made  by  super- 
saturating a  very  thick  milk  of  lime  with  sulphuretted 
hydrogen  gas.  The  apparatus  necessary  for  the  purpose 
consists  of  a  generator  and  a  receiver,  as  shown  in  the 
drawings  below.  Fig.  32  represents  a  leaden  generator, 
of  cylindrical  form,  and  about  thirty-six  inches  high,  by 
twenty-four  inches  diameter,  supported  by  a  wooden 
casing  or  jacket.  This  vessel  has  a  movable  cover  of 
cast-iron,  with  a  projecting  ledge,  through  which  pass 
the  bolts,  c,  c,  for  fastening  it  down.    In  this  cover  there 


SWELLING,  OR  RAISING. 
Fig.  82. 


173 


rr 


1 


IE 


c 


are  three  openings,  as  shown  by  Fig.  33.  The  larger 
one,  g,  is  the  man  hole,  for  the  admission  of  the  sul- 


phuret  of  iron,  and  for  cleaning  out.  Of  the  two  smaller, 
the  centre  one,  c7,  receives  the  stationary  funnel  tube, 
through  which  the  dilute  sulphuric  acid  is  to  be  intro- 
duced. The  side  hole,  ^,  contains  a  short  tube,  with 
a  screw  at  its  upper  end,  for  coupling  the  flexible  exit 
tube,  m  (made  of  lead,  or,  what  is  much  better,  vulcan- 
ized caoutchouc),  which  is  to  convey  the  generated  gas 
into  the  lime  paste,  contained  in  the  closely  covered 
receiver,  x.    The  pipe,  o,  running  down  the  side  of  the 


Fig.  33. 


174 


SWELLING,  OR  RAISING. 


generator,  interiorly,  is  for  the  coupling  of  the  steam 
conduit,  when  the  admission  of  steam  is  desirable. 

The  protosulphuret  of  iron,  a  cheap  material,  sold  at 
the  rate  of  five  dollars  per  hundred  weight,  rests  upon 
the  bottom  of  the  generator,  as  shown  at  s.  It  consists 
of  iron  and  sulphur  in  combination.  When  the  sul- 
phuric acid  and  water  (in  mixture  of  one  volume  of  the 
former  to  three  or  four  volumes  of  the  latter)  are  poured 
in  through  the  funnel  tube,  cZ,  to  the  height  indicated  in 
the  figure,  chemical  action  immediately  ensues.  The 
water,  which  is  composed  of  oxygen  and  hydrogen,  is 
decomposed,  and  the  former  gas  goes  at  once  to  the  iron, 
which  is  deserted  simultaneously  by  its  sulphur,  and 
thus  becoming  an  oxybase,  indulges  its  affinity  for  the 
sulphuric  acid,  and  unites  with  it  to  form  sulphate  of 
iron  or  copperas.  The  hydrogen  disengaged  from  its 
oxygen,  seizes  on  the  sulphur  at  the  moment  of  its  eli- 
mination, and,  uniting  chemically  with  it,  forms  sul- 
phuretted hydrogen,  and  makes  its  exit  through  the  tube, 
m,  leading  into  the  lime-milk,  with  which  it  combines 
as  hydrosulphuret  of  calcium.  The  current  of  gas  must 
be  uninterrupted  until  the  complete  supersaturation  of 
the  lime,  which  may  be  known  when  a  small  portion 
taken  out,  and  exposed  for  fifteen  minutes  to  the  air, 
still  emits  the  characteristic  fetid  odor  of  sulphuretted 
hydrogen  gas.  Whenever  the  flow  of  gas  slackens,  it 
must  be  hastened  by  pouring  in  a  small  quantity  of  un- 
diluted acid.  The  occasional  admission  of  steam  through 
the  pipe,  o,  by  applying  heat,  promotes  the  reaction. 
When  the  paste  is  saturated,  the  connection  of  the  pipes 
m  and  7c  must  be  severed,  and  the  generator  emptied  of 
its  contents,  through  the  ma7i  hole,  g,  so  that  it  may  be 
ready  for  a  fresh  charge  and  new  operation. 

The  receiving  vat  should  be  of  wood,  strongly  bound 


SWELLING,  OR  RAISING. 


175 


with  iron  hoops,  and  fitted  with  a  cover  and  appliances 
for  keeping  it  close  enough  to  confine  the  gas,  but  not  so 
tight  as  to  cause  an  explosion.  It  should  also  be  fitted 
with  a  revolving  stirrer  or  churn,  so  as  to  fiicilitate  the 
agitation  of  its  contents,  which  is  necessary  to  insure 
thorough  saturation  with  the  gas. 

The  paste  should  be  made  in  quantities  as  required, 
for  it  must  be  used  without  much  delay,  as  the  action  of 
the  air  soon  renders  it  inert,  by  converting  it  into  sul- 
phate of  lime. 

It  is  applied  to  the  green  or  softened  hides,  by  spread- 
ing them  upon  a  table,  and  paying  over  the  hair  sides 
with  a  thin  coating,  in  such  a  manner  that  it  may  reach 
the  surface  of  the  skin.  Two  skins  thus  treated,  are 
placed  with  their  hair  sides  together,  and  are  pressed 
between  boards.  In  two  hours  the  hair  is  entirely  loose ; 
and,  though  much  of  it  might  be  removed  by  mere 
washing,  it  is  necessary  to  scrape  in  the  usual  manner. 
The  paste  is  well  known  as  a  rapid  depilatory,  and  being 
totally  destitute  of  action  upon  the  hide,  it  leaves  its 
surface  smooth  and  uninjured.  This  process  is  highly 
commended  in  France;  but,  as  it  has  not  yet  been  used 
ill  this  country,  we  can  add  nothing,  from  experience,  in 
regard  to  it.  It  certainly  is  an  expeditious  plan,  and 
seems  so  feasible  and  economical  in  other  respects,  that 
we  recommend  the  trial  of  it  upon  a  large  scale. 

A  serious  inconvenience  in  the  use  of  this  paste  is  the 
offensive  and  unhealthy  odor  which  it  disengages ;  which, 
with  due  caution,  however,  may  be  avoided.  Sickness, 
colic,  and  pains  in  the  chest  are  some  of  its  ill  effects 
upon  the  system,  which  are  increased  to  asphyxia  or 
tetanic  convulsions,  when  the  odor  is  concentrated  and 
the  exposure  to  it  prolonged. 

Prof  J.  C.  Booth  [Encyclopedia  of  Chemistry^  p.  902), 


176 


SWELLING,  OR  RAISING. 


who  has  used  this  gas  extensively  in  manufacturing 
processes,  on  the  other  hand,  doubts  its  destructive  in- 
fluence upon  the  health,  unless  the  atmosphere  contain- 
ing it  is  surcharged  and  confined.  He  says  that,  "  al- 
though offensive,  it  may  be  inhaled  by  men,  when 
largely  mixed  with  air,  without  apparent  injury;  and, 
even  when  fresh,  it  may  be  respired  in  large  quantity, 
without  producing  any  other  eflect  than  a  temporary 
faintness.  The  effect  upon  one  workman  was  a  plea- 
sant, lethargic  feeling ;  and  I  have  breathed  a  strong 
mixture  of  it  with  air,  repeatedly,  and  never  experienced 
the  slightest  injury  to  my  health." 

Kefuse-lime  from  the  gas  works,  used  in  purifying  the 
gas,  contains,  when  fresh,  a  large  proportion  of  hydro- 
sulphuret  of  calcium;  and  might  be  substituted  for  the 
prepared  paste ;  but  it  is  very  slow,  and  much  less  cer- 
tain in  its  action. 

Warrington  s  Process. — Warrington  proposes  the  use 
of  carbonate  of  soda  or  potassa  for  soaking ;  and  the  em- 
ployment of  hydrochloric  or  nitric  acid,  and  also  certain 
vegetable  matters,  for  facilitating  d epilation,  and  pro- 
moting the  swelling.    See  Chapter  XIX.  for  details. 

Cool  Sweating  Process. — This  method  of  unhairing 
hides  has  been  in  general  use  for  some  time  in  New 
York,  New  Hampshire,  and  the  northern  part  of  Penn- 
sylvania ;  and  experience  confirms  all  the  advantages 
over  the  older  processes,  claimed  for  it  by  the  inventor. 
It  is  said  to  give  a  gain  in  the  leather  of  70  to  80  per 
cent,  on  the  dry  hide;  while  the  "warm  sweating"  pro- 
cess yields  much  less,  and  the  "liming"  only  30  to  40 
per  cent.  It,  moreover,  obviates  the  necessity  of  pre- 
viously subjecting  the  dry  hides  to  the  fulling  stocks, 
which,  by  producing  an  undue  distension,  renders  the 
leather  thin,  weak,  and  limber,  beyond  the  required  degree. 


SWELLING,  OR  RAISING. 


177 


The  process  and  apparatus,  the  description  of  which 
we  take  from  the  Journ.  Frank.  Bistit.,  1843,  are  as  fol- 
lows : — 

"  First,  a  vault  or  pit  should  be  prepared  for  the  re- 
ception of  the  hides;  which,  for  convenience  sake,  should 
be  twelve  feet  long,  twelve  feet  deep,  and  ten  feet  wide. 
The  walls  may  be  built  of  stone  or  of  a  planked  frame. 
There  should  be  one  alley,  or  vestibule,  for  entrance,  not 
less  than  six  feet  long,  having  a  door  at  each  end,  the 
outer  one  made  double,  and  filled  in  with  tan,  to  prevent 
the  communication  of  warm,  dry  air  from  without.  A 
ventiduct,  made  of  plank,  ten  or  twelve  inches  square, 
should  extend  from  the  centre  of  the  bottom  of  the 
vaults,  three  or  four  rods  therefrom,  and  placed  not  less 
than  four  feet  below  the  surface  of  the  ground.  This 
serves  both  as  a  drain  for  discharging  the  water  of  the 
vault,  and  to  admit  damp,  cool  air,  to  supply  the  place 
of  that  which  has  become  rarefied,  and  thus  keep  up  a 
current  through  the  ventilator  at  top.  The  ridge  of  the 
roof  may  be  level  with  the  surface  of  the  ground ;  and, 
on  the  ridge,  extending  its  whole  length,  set  up  two 
planks  edgewise,  two  inches  apart.  The  space  between 
these  is  to  be  left  open,  but  the  remainder  of  the  roof 
must  be  covered  with  earth,  to  the  depth  of  at  least  a 
yard.  The  earth  covering  upon  the  vault  and  drain  is 
to  preserve  a  low  temperature  for  the  hides,  so  that  they 
may  unhair  without  tainting.  Spring-water  should  be 
conducted,  either  in  pipes  or  logs,  around  the  angles 
formed  by  the  ceiling  with  the  walls  of  the  vault,  from 
which  water  should  be  allowed  to  flow  in  small  quan- 
tities, either  forming  a  spray,  or  falling  so  as  to  raise  a 
mist  or  vapor,  and  saturate  the  atmosphere  of  the  vault. 
The  temperature  of  spring-water  is  generally  about  50° 
F.    Water  evaporating  at  all  temperatures,  it  is  plain 


178 


SWELLING,  OR  RAISING. 


that,  if  a  constant  supply  be  afforded,  this  evaporation, 
by  requiring  a  large  portion  of  heat,  would  keep  the 
temperature  of  the  vault  nearly  uniform.  To  suspend 
the  hides  in  the  pit,  place  three  bars  lengthwise,  at  equal 
distances,  near  the  ceiling,  with  iron  hooks,  two  or  three 
inches  apart,  inserted  therein.  Soak  the  hides  as  usual 
for  breaking,  then  hang  them  singly  upon  the  hooks  by 
the  butt,  so  that  they  may  be  spread  fully  open.  In 
the  course  of  a  few  days,  when  the  hair  begins  to  loosen 
upon  the  upper  parts,  take  them  down,  raise  the  middle 
bar,  and  hang  them  by  the  other  end,  until  they  will 
easily  unhair.  The  hides  should  not  be  broken  until 
they  are  taken  from  the  vault  and  ready  to  unhair.  In 
a  good  vault,  where  the  thermometer  ranges  from  44°  to 
56°  F.,  which  it  should  never  exceed,  and  where  there 
is  a  free  circulation  of  damp  air,  hides  generally  require 
six  to  twelve  days  for  unhairing.  When  the  tempera- 
ture falls  below  44°,  the  ventilator  should  be  partially 
closed;  and  when  it  rises  above  56°,  cold  damp  air  must 
be  forced  in,  or  an  increased  quantity  of  cold  spring-water 
may  be  thrown  from  a  hose  or  otherwise." 

The  hides  carefully  carried  through  this  process,  when 
received  by  the  tanner  from  the  beamsman's  hands,  are 
free  from  all  extraneous  matter,  and  contain  all  their 
gelatine,  albumen,  and  fibrine,  in  an  unimpaired  state. 
It  is  not,  as  the  inexperienced  suppose,  a  fermentation 
which  produces  the  unhairing,  for  there  is  no  ammonia 
generated,  and  this  is  universally  a  product  of  the  putre- 
factive decomposition  of  animal  matters.  "  The  action 
is  confined  to  the  surface  or  grain  of  the  skin,  expanding 
the  outer  portion,  softening  the  roots  of  the  hair,  and 
thus  rendering  its  removal  easy.  Its  effect  is  due  to  the 
softening  action  of  the  vapor,  and  it  is  a  simple  case  of 


SWELLING,  OR  RAISING. 


179 


absorption  and  swelling  of  the  tissues  of  the  skin  and 
roots  of  the  hair." 

Liming,  which  requires  an  immersion  of  three  or  more 
weeks,  it  is  true,  loosens  the  epidermis  and  hair,  and 
renders  their  removal  easy  by  fleshing;  but,  at  the  same 
time,  injures  the  gelatine  and  albumen,  and  "  swells"  the 
hide  so  excessively,  and  expands  its  texture,  as  to  weaken 
the  leather.  Moreover,  if  it  should  be  what  is  termed 
high  limed,  the  leather  is  light,  and  not  durable;  bad 
properties,  which  it  also  possesses,  but  in  a  modified 
degree,  even  when  prepared  by  Icnv  limiiig.  More- 
over, the  ill  effects  of  the  hating  which  follows,  are  an 
additional  drawback.  The  bate  consists  of  a  liquor 
made  from  the  dung  of  domestic  fowls,  and  immersion 
in  this  removes  the  lime  and  reduces  the  skin  to  its 
original  thickness.  It  acts  by  means  of  the  muriate  of 
ammonia  which  it  contains.  This  salt  is  decomposed 
by  the  lime,  which  drives  off  its  base,  the  ammonia,  and 
taking  up  with  the  muriatic  acid,  then  becomes  soluble 
muriate  of  lime,  and  passes  off  with  the  rinse  water;  but 
carries  with  it,  at  the  same  time,  a  portion  of  the  gela- 
tine, rendered  soluble  by  the  putrefaction  of  the  organic 
matter  of  the  bate,  which  undoubtedly  occurs.  There 
is  emitted,  besides,  an  offensive  odor,  which  is  injurious 
to  the  health  of  the  workmen. 

Suspending  the  hides  in  close  chambers,  heated  slightly 
above  the  ordinary  temperature  of  the  atmosphere,  and 
thus  loosening  the  epidermis  by  incipient  putref\iction, 
is  as  objectionable  as  the  liming  or  bating  process. 

The  German  method  of  sweating  the  hides  in  piles, 
or  stacks,  under  a  covering  of  tan  or  some  other  imper- 
fect conducting  material,  in  order  to  confine  the  heat 
generated  by  the  chemical  decomposition  going  on  within, 
is  fully  as  disadvantageous  as  either  of  the  foregoing. 


180 


SWELLING,  OR  RAISING. 


The  present  process,  its  author  says,  has  been  proved 
by  experience,  to  obviate  all  the  evils  arising  from  "  hot 
sweating,"  or  from  unhairing  the  hides  by  the  lime 
process. 

Yauquelin  proposes  the  substitution  of  machinery  for 
the  use  of  lime,  arsenic  acid,  and  salts;  but  we  shall 
delay  a  description  of  it  until  we  come  to  speak  of  his 
process  for  tanning. 

Turnbull,  taking  advantage  of  the  property  which 
sugar  possesses  of  forming  a  soluble  saccharate  of  lime, 
employs  it  for  removing  any  excess  of  that  base  which 
may  remain  in  the  hide.  This  process,  of  which  we 
shall  speak  more  fully  hereafter,  is  said  to  be  expensive ; 
but  it  shortens  the  time  of  tanning,  and  improves  the 
quality  of  the  leather. 

Raising  hy  Barley  Dressings. — The  raising  and  depila- 
tion  of  hides  by  barley  is  more  effective  and  rapid  than 
when  lime  is  used.  It  is  a  common  error  that  hides,  treated 
in  this  manner,  require  more  working  in  the  water.  In- 
deed, the  very  reverse  being  frequently  the  case. 

There  should  be  a  series  of  vats  of  this  acid  liquor, 
varying  in  strength.  The  hides  are  first  soaked  in  the 
vat  containing  the  weaker  liquor,  then  pressed,  and 
afterwards  washed.  After  several  repetitions  of  these 
manipulations,  the  hair  becomes  loose,  and  easily  re- 
movable from  the  skins. 

In  the  tannery  of  Bouillerat,  at  Paris,  the  proceeding 
is  as  follows  :  The  hides,  as  they  come  from  the  slaughter- 
house, after  being  soaked  and  fleshed,  are  put  through  the 
dressings,  that  is,  subjected  to  the  action  of  fermentable 
barley  water. 

They  remain  three  days  in  the  first  or  dead  dress- 
ing," and  as  much  longer  in  the  second,  when  they  are 
freed  from  their  hair,  and  placed  in  a  third  vat,  in  which 


SWELLING,  OR  RAISING. 


181 


they  dilate,  swell  out,  and  acquire  consistence.  They 
are  taken  out  only  once,  daily,  from  the  dead  dressing, 
and  twice  from  the  others.  At  each  time  they  are  laid 
in  heaps,  and  there  left  in  retreat^  during  an  interval  of 
three  hours.  After  these  three  dressings,  the  hides  are 
subjected  to  a  fourth,  which  is  termed  the  new  dressing. 
This  latter  is  made  with  145  pounds  of  well-ground 
barley  meal.  From  this  quantity  10  pounds  are  taken 
out  and  made  into  a  leaven,  by  being  kneaded  with 
warm  water,  and  left  to  ferment  for  twelve  to  fourteen 
hours,  in  which  time  it  sours  and  becomes  sufficiently 
ripe  for  the  operation.  This  leaven  is  thinned  out,  in 
winter  with  boiling,  in  spring  with  hot,  and  in  summer 
with  tepid  water,  in  sufficient  quantity  to  form  the 
dressing.  The  vats  for  these  operations  are  iron-bound 
cedar  tubs. 

The  hides  are  passed  from  the  new  dressing  into  an- 
other similar  one,  and  are  allowed  to  remain  four  days 
in  eatjh.  Eight  or  nine  hides  are  generally  worked  at 
one  time. 

The  series  is  composed  of  four  or  five  tubs,  or  vats. 
The  first  dressing  is  intended  to  wash  the  hides,  the 
second  for  depilation,  the  third  to  swell  them  and  impart 
body;  and  the  two  others,  which  are  new,  complete  the 
action  of  the  third.  These  preparations,  termed  white 
dressings,  require  five  weeks  in  summer  and  six  in 
winter.    Fig.  29  represents  the  dressing  series. 

After  having  gone  through  the  white  dressings,  as 
above,  the  hides  are  carefully  washed  and  placed  in  the 
red  preparation,  composed  of  220  pounds,  or  four  baskets, 
of  tan,  well  mixed  with  two  and  a  half  hogsheads  of 
water;  and  are  left  in  the  mixture  for  fifteen  days  during 
summer,  and  for  one  month  in  the  winter.  It  is,  how- 
ever, necessary,  during  the  first  five  days,  to  take  the 


182 


SWELLING,  OR  RAISING. 


hides  out,  once  daily,  in  order  to  be  assured  that  the 
supply  of  bark  is  sufficient.  When  the  skins  come  from 
the  preparation,  they  are  to  be  washed  and  placed  in  the 
vats.  Eight  or  nine  skins  may  be  handled  at  one  work- 
ing. 

At  Abbeville,  which  is  renowned  for  the  number  of 
its  tanneries,  and  the  quality  of  its  leather,  the  tanners 
adopt  the  following  method  : — 

For  sixteen  hides,  48  pounds  of  unbolted  barley  meal 
are  put  into  an  open-mouthed  tub  or  hogshead,  and 
mixed  with  some  sour  paste,  made  of  flour,  thinned  out 
with  hot  water.  To  this  mixture  about  half  a  pound  of 
yeast  is  added ;  fermentation  soon  follows,  and  in  from 
fifteen  to  sixteen  hours  the  leaven  is  formed.  This 
leaven  being  thoroughly  mixed  with  150  pounds  of  meal, 
in  a  tub  of  water,  forms  what  is  termed  the  new  dressing 
or  preparation. 

The  same  gradation  as  with  lime  is  observed  as  to 
these  dressings.  Before  the  hides  are  worked,  Hhey 
should  be  cut  into  halves,  and  always  placed  with  the 
flesh  side  upwards. 

The  hides  remain  two  or  three  days  in  the  old,  five  or 
six  days  in  the  weak,  and  twelve  or  fifteen  in  the  third 
and  fourth,  which  are  the  strong  or  new  dressings.  Some- 
times the  hides  are  sufficiently  raised  at  the  fourth  dress- 
ing, and  then  they  are  taken  out,  while  the  unfinished 
ones  are  put  into  a  fifth  dressing,  and  left  until  they 
have  acquired  sufficient  swelling.  During  summer,  the 
hides  are  drawn  out  twice,  and  in  winter  once,  and  left 
to  drain  for  an  hour,  each  time,  upon  a  trough  conve- 
niently situated  near  the  tub.  The  course  of  barley- 
dressings  requires  about  six  weeks  in  summer,  and  much 
longer  in  winter,  for  cold  retards  their  action. 

According  to  Delalande,  in  Sedan  they  use  nine  or  ten 


SWELLING,  OR  RAISING.  183 

small  tubs,  of  about  six  hogsheads  each.  There  is  a 
regular  gradation  in  their  strength ;  for  example,  after 
the  first  operation,  the  second  becomes  the  first,  the 
third  second,  and  so  on  progressively. 

Five  hides  are  placed  in  the  first  tub,  and,  after  re- 
maining therein  from  twenty-four  to  forty-eight  hours, 
are  transferred  to  the  second,  which  is  a  little  more  sour, 
then  to  the  third,  and  so  on  successively,  through  all  the 
remaining  tubs,  until  they  have  passed  through  the 
whole  ten.  The  last,  as  we  have  already  said,  is  always 
the  strongest,  and  the  first  the  weakest. 

If,  as  often  happens,  the  skins  should  attain  the  ne- 
cessary degree  of  dressing  at  the  fourth,  third,  or  even 
second  tub,  it  is  needless  to  treat  them  further.  These 
sour  liquors,  even  after  having  served  for  ten  successive 
operations,  still  retain  acidity,  and  are  again  applicable, 
in  proportion  to  their  degree  of  strength,  which  must  be 
determined  by  the  experience  of  the  workman. 

All  tanners  are  not  agreed  as  to  the  exact  time  for 
depilation ;  some  proceed  to  this  step  after  the  second 
dressing,  while  others,  holding  to  the  old  adage,  that  the 
hides  raise  better  with  the  hair  on  than  in  pelt,  do  not 
dehair  until  after  the  dressing  before  the  last. 

After  the  skins  have  been  treated,  they  are  washed 
in  clear  water,  for  the  removal  of  dirt;  and,  when  they 
come  from  the  last  dressing,  they  are  again  rinsed  and 
scraped  over  with  the  fleshing-knife,  Fig.  26.  Finally, 
they  are  again  put  in  water,  and  brushed  over  on  the 
hair  side. 

Some  few  tanners,  after  this  manipulation,  lay  the 
hides  in  the  vats;  but  the  majority  first  subject  them 
to  a  red  dressing.  This  latter  dressing  is  given  by 
spreading  the  hides  in  a  vat,  one  above  another,  and 
placing  between  each  pair  two  or  three  handfuls  of  ground 


184  SWELLING,  OR  RAISING. 


Fig.  34. 


bark.  Water  is  then  added  until  the  hides  are  sub- 
merged. This  process  requires  two  days,  and  the  hides 
require  only  one  withdrawal  to  allow  them  to  drain. 
In  giving  them  the  finishing  wet,  care  must  be  observed 
to  supply  bark  where  it  may  be  wanting. 

This  method  of  cleaning  and  unhairing  is  equally 
objectionable  as  the  lime  process;  and  has,  besides, 
additional  disadvantages.  Exposure  to  a  very  low  tem- 
perature destroys  the  efficacy  of  the  bath,  which  is  not 
restored,  as  in  the  case  of  lime,  when  the  bath  thaws. 
And  the  leather  is  also  exposed  to  the  risk  of  being  in- 
jured by  the  putrefactive  fermentation  of  the  materials. 

The  English  have,  for  a  long  time,  used  the  barley 
dressings  for  their  coarse  hides ;  but,  with  them,  the  ope- 
ration of  raising  is  completed  in  six  days.  The  hides 
pass  through  four  or  five  dressings,  and  progressively 
from  the  weak  to  the  strong  preparations.  The  hides 
remain  only  twenty-four  hours  in  the  last  vat,  which  is 
new,  and  which  has  been  soured  for  fifteen  days.  It  is 
made  by  diffusing  about  sixty  pounds  of  barley  meal  in 
hot  water.  As  a  long  time  is  allowed  for  the  develop- 
ment of  acid,  and,  consequently,  the  dressing  is  more 
active  than  ordinary  ones,  it  becomes  necessary  to  watch 
carefully  when  the  required  point  is  reached,  otherwise 
the  hides  will  suffer  injury. 

Barrois,  an  eminent  French  tanner,  pursued  a  method 


SWELLING,  OR  RAISING. 


185 


somewhat  different  from  the  preceding.  According  to 
Delalande,  he  worked  five  series,  of  four  tubs  each,  at  a 
time.  These  tubs  were  three  feet  and  a  quarter  in  height, 
and  five  feet  in  diameter,  and  of  capacity  for  eight  hides ; 
each  series  comprising  thirty-two  hides.  It  is  necessary 
to  take  out  all  the  hides,  twice  daily,  during  the  dress- 
ing. 

Every  four  days  a  new  preparation  is  made  up  in  one 
of  the  four  tubs ;  it  is  deposited  in  that,  the  dressing  of 
which  was  the  weakest,  after  running  it  off  and  washing 
out  the  vat.  The  third  vat  then  becomes  the  last  or 
weakest,  and  that  which  was  the  first  and  strongest,  be- 
comes the  second. 

The  eight  hides  remain  eight  days  in  the  fourth  or 
weakest  vat;  four  days  in  the  third,  which  then  becomes 
the  weakest ;  then  the  same  length  of  time  successively 
in  the  second  and  the  first,  after  six  days'  residence  in 
which,  they  are  stripped  and  deposited  in  the  fresh  series. 
In  this  they  remain  four  days,  in  a  dressing  which  has 
only  been  used  once ;  four  days  more  in  another  similar 
one  ;  and  four  days  each,  in  two  fresh  vats. 

Each  fresh  preparation  for  eight  hides,  is  composed  of 
145  pounds  of  ground  barley,  and  the  leaven  is  made 
with  30  pounds  of  this  quantity,  mixed  with  yeast  and 
hot  water. 

This  interval  of  thirty-two  days  suffices  for  the  requi- 
site preparation  of  the  hides,  either  in  summer  or  winter ; 
but,  in  the  latter  season,  hot  water  is  generally  used  in 
the  proportion  of  five  or  six  bucketsful  to  each  prepara- 
tion, in  order  to  hasten  the  fermentation. 

A  barley-dressed  hide  of  100  pounds,  takes  about  200 
pounds  of  bark,  as  follows :  25  in  the  red  dressing,  30  in 
the  first  powder,  25  in  the  second,  and  20  in  the  third. 
13 


186 


SWELLING,  OR  RAISING. 


The  freshness  of  the  preparations  may  be  maintained  by 
the  occasional  addition  of  a  few  pints  of  good  vinegar. 

After  the  hides  have  been  sufficiently  raised  in  the 
white  dressings,  they  are  put  in  the  red.  This  latter  is 
composed  of  clear  water,  and  two  or  three  handfuls  of 
bark  placed  between  each  hide.  The  hides  remain  thus 
for  three  or  four  days,  when  they  are  again  treated  with 
the  same  quantity  of  bark  as  at  first,  and  left  for  three 
days  longer;  after  which  time  they  are  ready  to  be  laid 
in  the  vats,  in  the  same  manner  as  limed  hides.  The 
red  dressings  impart  that  degree  of  firmness  which  pre- 
vents the  too  rapid  action  of  the  tan  liquor,  and  the 
hardening  of  the  hides. 

With  some  slight  modifications,  this  process  is  one  of 
the  best  that  can  be  followed.  For  example,  a  fresh  vat 
may  be  used  every  two  days,  and  thus  there  will  be  a 
gain  of  half  of  the  time.  Instead  of  clear  water,  it  would 
be  much  better  to  use  the  liquor  of  the  tan-pits,  and  to 
place  between  each  hide  a  layer  of  coarsely  ground  bark 
for  the  red  dressings. 

We  will  remark  that  200  pounds  of  bark  are  not  suf- 
ficient for  100  hides,  averaging  100  pounds  each.  In 
some  places  they  use  as  much  as  300  pounds ;  but  the 
proper  quantity  depends  very  much  upon  the  quality  of 
the  bark  and  the  fineness  of  its  powder. 

The  following  is  a  method  which  may  be  well  adopted 
by  those  who  prepare  hides  with  the  barley  dress- 
ings : — 

For  a  dressing  for  eight  hides,  averaging  50  pounds 
each,  from  100  to  140  pounds  of  barley  meal  must  be 
employed.  Some  tanners  use  all  the  meal  at  once; 
but  others  again  make  a  leaven  with  24  pounds  of  the 
meal,  which  they  do  not  mix  with  the  rest  until  twelve 
hours  have  elapsed.    Many  tanners  keep  up  the  acidity 


SWELLING,  OR  RAISING.  187 

of  the  dressings  by  throwing  into  each  one  three  or  four 
bottles  of  vinegar,  at  different  times. 

This  is  a  very  good  way  of  increasing  the  acidity  of 
the  bath,  and  shortening  the  operation. 

Other  manufacturers,  without  giving  themselves  the 
trouble  of  making  a  separate  leaven,  put  the  whole  of 
the  meal  in  the  tub,  and  drench  it  with  enough  tepid 
water  to  form  a  fermentable  paste,  and  leave  it  in  this 
state  for  twenty-four  hours.  The  dressing  is  then  made 
by  adding  to  the  fermented  farina  warm  water  in  win- 
ter, and  water  of  the  temperature  of  the  atmosphere  in 
summer.  The  quantity  of  water  must  be  regulated  by 
the  number  of  hides  to  be  worked.  These  should  be 
'divided  into  two  sides,  before  subjecting  them  to  the 
dressings,  wherein  they  must  remain  three  weeks  in 
summer  and  four  in  winter.  To  facilitate  the  fermenta- 
tion, the  hides  should  be  taken  out  daily,  placed  on 
planks  across  the  vats,  as  shown  by  Fig.  35,  and  there 


Fig.  35. 


left  for  two  or  three  hourg.  The  vats  should  be  four 
feet  and  a  quarter  in  height,  and  as  much  in  diameter. 
In  some  countries,  the  tanners  use  nine  or  ten  tubs, 
but  three  are  sufficient;  the  first  for  the  c?eac?  prepara- 
tion, the  second  for  the  feeble  one,  and  the  third  for  that 
termed  the  new  dressing.  The  only  rule  that  can  be 
given  for  depilation,  is  to  operate  as  soon  as  the  hair 


188 


SWELLING,  OR  RAISING. 


can  be  pulled  off  without  resistance,  a  condition  attained 
frequently  after  the  second,  and  even  the  first  dressing. 

The  hides  are  then  scraped,  with  the  usual  precau- 
tions, with  the  round  knife,  and  are  then  thrown  into 
water,  in  which  they  should  not  be  allowed  to  remain 
more  than  two  hours. 

They  are  then  carefully  rinsed,  drawn  out,  and  placed 
in  the  second  or  weak  preparation.  If  the  tannery  is 
not  in  the  vicinity  of  a  stream  of  running  water,  the 
repeated  use  of  clean  water  must  be  substituted  for 
soaking  the  hides. 

The  experience  of  the  workmen  must  determine  the 
length  of  time  necessary  for  the  weak  bath.    While  they 
are  attaining  the  requisite  body,  they  must  be  taken  out' 
daily,  and  again  replaced  in  the  vats. 

If  they  had  not  been  fleshed  before  the  dressings,  it  is 
necessary  to  subject  them  to  this  operation,  after  draw- 
ing them  from  the  weak  vat ;  but  it  is  better  always  to 
do  it  previously.  After  the  fleshing,  they  are  soaked  in 
water  for  two  hours,  then  rinsed  carefully,  and  placed 
in  the  third,  which  is  the  new  dressing.  It  is  prepared 
with  barley  meal,  in  the  proportion  of  twelve  pounds  for 
each  hide.  A  leaven  is  made  with  one-fourth  of  this 
quantity  of  meal,  and  when  it  begins  to  ferment,  the 
residue  is  added,  and  the  whole  thoroughly  diffused  in 
an  amount  of  water  proportional  to  the  number  of  hides 
to  be  worked. 

The  exact  time  requisite  to  complete  the  swelling  of 
the  hides,  in  the  third  dressing,  cannot  be  determined ; 
for  it  varies  with  the  nature  of  the  skins,  the  season, 
&c.;  and  must,  therefore,  be  regulated  by  the  judgment 
of  the  workman. 

The  hides  during  this,  as  in  other  dressings,  should 
be  daily  removed  from,  and  replaced  in  the  vats. 


SWELLING,  OR  RAISING. 


189 


The  hides,  after  passing  through  the  first  three,  or 
white  dressings,  are  then  put  into  the  red,  which  is 
made  of  liquor  from  the  tan-vats,  to  which  must  be 
added  about  forty  pounds  of  coarse  bark  for  every  six 
hides. 

Care  must  be  taken,  in  this  manipulation,  to  avoid 
delay,  and  not  to  give  the  bark  time  to  subside  to  the 
bottom  of  the  vat,  for  then  the  skins  will  be  unequally 
tanned. 

To  prevent  this,  it  is  best  to  commence  work  with  the 
red  dressing,  very  early  in  the  morning,  so  that  the  ope- 
ration may  be  completed  before  night,  and  the  necessity 
of  leaving  the  skins  in  too  long  without  stirring  be  thus 
avoided.  By  this  arrangement,  the  hides  may  be  taken 
out  and  replaced  twice  daily,  once  in  the  forenoon,  and 
again  in  the  afternoon.  The  first  time,  they  are  al- 
lowed to  drain  for  eight  to  ten  minutes,  while  the  dress- 
ing is  being  stirred,  and  are  then  immediately  replaced. 
The  second  time  they  are  taken  out,  fifteen  minutes  are 
allowed  for  draining,  and,  in  the  interval,  forty  pounds 
of  coarse  bark  are  added,  and  the  vat  is  thoroughly 
stirred. 

The  next  day  and  the  day  after,  the  skins  are  taken 
out  and  put  back  again  three  times  daily — at  morning, 
noon,  and  evening — and  left  to  drip  an  half  hour  each 
time.  Twenty-five  pounds  of  fresh  bark  are  added  in 
the  morning  only ;  but,  upon  every  removal  of  the  hides, 
the  dressing  must  be  carefully  stirred.  No  bark  is  to  be 
added  on  the  fourth  day;  and  the  hides  are  taken  out 
only  twice,  in  the  morning  and  evening,  but  are  allowed 
to  drain  three-quarters  of  an  hour  each  time.  During 
the  intervals,  the  vat  must  be  stirred  before  the  hides 
are  put  back.  The  last  step,  upon  the  fifth  day,  requires 
a  new  manipulation.    After  the  hides,  taken  out  in  the 


190 


SWELLING,  OR  RAISING. 


morning,  have  drained  for  three-quarters  of  an  hour, 
two  workmen  on  one  side  of  the  vat  are  engaged  in 
stirring  up  the  contents,  while  two  others  put  back  the 
hides,  flesh  sides  down,  care  being  taken  to  spread  some 
handfuls  of  bark  upon  each.  When  the  vat  is  full,  the 
last  skin  is  put  in,  reversed,  with  the  hair  side  down, 
and  some  bark  is  sprinkled  over  it.  After  ten  days,  the 
hides  are  taken  out,  rinsed  in  water  which  has  been 
used  for  a  dressing,  and  laid  in  the  vats.  This  is  termed 
the  coloring.  About  fifty  pounds  of  coarse  bark  are 
generally  consumed  in  the  last  dressing. 

The  red  dressing  is  a  very  important  step  in  the  pro- 
cess of  tanning.  It  gives  firmness  to  the  hide,  by  an 
incipient  tanning,  which  serves  as  preliminary  to  that 
which  is  to  follow.  According  to  Delalande,  a  skin 
which  has  not  received  a  red  dressing,  is  tanned  so 
rapidly  that  it  shrinks,  becomes  hard,  wrinkled,  and 
insusceptible  of  perfect  combination  with  the  astringent 
principle  of  the  tan.  Experienced  tanners  aver  that  these 
faults  arise  rather  from  giving  too  strong  a  dressing,  than 
from  having  the  vats  too  strong.  The  feeding  of  a  vat, 
according  to  Dessable,  can  never  be  too  strong,  for  the  hide 
neither  hardens  nor  shrinks  in  the  powder.  We  agree 
wdth  him  in  part,  but  believe  that  a  strong  feeding  of 
the  vat  is  injurious.  Experience  proves  that  if  the  hide 
be  directly  subjected  to  contact  with  a  concentrated 
liquor  of  bark,  the  operation  of  the  tannin  is  very  active, 
but  its  combination  with  the  gelatine  is  so  rapid  upon  the 
exterior  surfaces,  that  the  interior  is  unacted  upon,  as  is 
the  case  in  hasty  tanning,  where  processes  like  that  of 
I  Seguin  are  followed. 

The  red  dressing  is,  therefore,  a  primary  degree  of 
tanning,  which  should  be  succeeded  by  the  stronger  ones. 
The  hides,  consequently,  are  to  be  placed  immediately 


SWELLING,  OR  RAISING. 


191 


in  the  vats,  in  the  same  manner  as  limed  hides.  It  is 
well  to  add,  that  there  is  no  necessity  of  covering  the 
red  dressings,  but  they  must  be  ke'pt  filled  to  within  two 
inches  of  the  top  of  the  tubs. 

There  are  some  tanners  who  contend  that  barley- 
dressed  hides  require  about  20  per  cent,  more  bark  than 
those  which  have  been  limed.  In  many  tanneries,  they 
take  for  a  barley-dressed  hide,  averaging  100  pounds  in 
weight,  224  pounds  of  bark,  as  follows :  84  pounds  for 
the  first,  74  pounds  for  the  second,  and  66  pounds  for 
the  third. 

The  same  results  are  to  be  obtained  with  rye  flour; 
but  that  grain  being  expensive,  barley  is  substituted 
for  it. 

The  descriptions  of  these  various  dressings  have  been 
given  more  for  the  purpose  of  making  known  the  pro- 
cesses employed  in  different  countries,  than  of  recom- 
mending them  to  manufacturers.  Their  use  is  now  very 
generally  abandoned,  in  consequence  of  the  uncertainty 
of  their  action,  and  the  injurious  effects  which  atmo- 
spheric changes  exert  upon  them.  We  accordingly 
proceed  to  the  consideration  of  more  advantageous  and 
commonly  used  methods  of  procedure. 

Raising  hy  Sour  Tan-liquor. — This  method  of  depriv- 
ing skins  of  hair,  and  raising  them  by  the  action  of  tan- 
liquor,  was  first  practised  in  Germany,  but  has  since 
been  adopted  and  generally  resorted  to  in  many  parts  of 
France. 

Its  use  presents  more  difliculties  than  other  processes, 
but  may  be  regarded  as  advantageous  in  the  extreme, 
since  it  is  actually  the  commencement  of  the  main  tan- 
ning operations,  and  serves  to  abridge  the  time  occupied 
by  them ;  and  since  the  leather  prepared  by  it,  is  much 
superior  in  quality  to  that  treated  by  liming,  or  by  bar- 


192  SWELLING^  OR  RAISING. 

ley  or  rye  dressing.  As  the  various  processes  of  this 
method  cannot  be  too  well  known,  we  propose  to  de- 
scribe them  minutely  and  fully,  commencing  with  the 
account  of  those  originally  employed. 

The  first  process  we  shall  describe,  is  extracted  from 
a  memoir  by  Champion. 

When  this  method  was  first  employed  in  France,  the 
skins  were  deprived  of  hair  by  the  action  of  heat,  and 
in  order  to  prevent  putrefaction,  from  one  pound  to  a 
pound  and  a  half  of  salt  were  sprinkled  over  one-half  of 
the  surface  of  each  skin,  the  other  half  being  turned  over 
upon  it,  and  the  edges  brought  together  so  as  to  prevent 
the  escape  of  the  salt.  From  15  to  20  skins  were  salted 
in  this  manner  and  placed  one  above  the  other;  being 
left  in  this  position  during  four  or  five  hours  in  spring 
and  autumn,  and  seven  or  eight  in  winter,  the  operation 
never  being  conducted  in  summer.  At  the  end  of  this 
time,  the  skins  were  folded  again  in  the  opposite  direc- 
tions, the  bellies  being  placed  upon  the  backs,  and  the 
heads  under  the  tails,  and  the  whole  being  piled  upon 
one  another  so  as  to  be  exposed  equally  to  heat. 

The  skins  were  first  dried  with  the  hair  on,  and  were 
then  soaked  for  eight  hours  in  running  water ;  were 
beaten  with  the  feet  or  the  mace,  and  again  soaked 
during  four  or  five  hours.  They  were  then  beaten  a 
second  time,  rinsed,  and  drained  upon  the  horse,  after 
which  they  were  salted  as  before  described.  After  being 
freed  from  hair  by  the  influence  of  heat,  to  which  they 
were  exposed  in  a  tight,  vaulted  apartment,  they  were 
soaked  in  running  water. 

After  these  preparatory  processes,  the  skins  were  then 
subjected  to  the  steeping  in  sour  tan-liquor,  which  softens 
and  enlarges  the  fibre,  opens  the  pores,  and  raises  them 
sufficiently  to  receive  the  first  tanning. 


SWELLING^  OR  RAISING. 


193 


Another  method  is  to  deprive  the  skins  of  hair,  by 
stacking  them  in  heaps  (Fig.  36),  and  promoting  warmth 


Fig.  36. 


by  covering  them  with  straw  or  manure,  their  position 
being  changed  every  day,  until  the  hair  is  ready  to  be 
removed.  If  it  comes  off  with  difficulty  upon  the  horse, 
its  separation  is  facilitated  by  the  use  of  sand  spread 
upon  the  hair  side.  This  method  of  removing  the  hair, 
however,  is  the  most  disadvantageous  of  any  employed, 
as  the  skins  are  very  apt  to  be  injured  by  it. 

In  order  to  prepare  the  tan  liquor  for  the  baths,  the 
bark  which  has  been  used  for  the  second  or  third  set  of 
vats  in  the  tanyard,  is  deposited  in  a  vat,  so  arranged 
that  the  liquor  percolating  through  it  may  be  received 
in  a  draining-well  or  vessel  placed  under  it,  from  which 
it  can  be  returned  into  the  main  receptacle  again  and 
again,  so  as  to  secure  an  increase  of  strength  by  repeated 
filtrations  and  solutions.  This  liquor,  when  of  the 
proper  strength,  should  be  of  a  clear  red  color,  and  of 
an  acid  taste  like  that  of  good  vinegar,  and  from  this  a 
number  of  baths  may  be  made  of  different  strengths. 
For  instance,  a  series  of  eight  baths  may  be  made,  the 
first  one  containing  one  part  of  the  liquor  and  seven  of 
water,  and  so  on  until  the  full  strength  is  arrived  at. 

When  the  skins  are  freed  from  hair,  washed,  and 
fleshed,  they  are  soaked  in  clear  water,  for  two  days  in 
summer,  and  four  or  five  in  winter,  the  water  being 
changed  every  day,  and  the  skins  left  to  drain  during 


194 


SWELLING,  OR  RAISING. 


three  hours.  When  the  skins  are  ready  for  raising^ 
after  being  steeped,  they  are  deposited  in  vats  containing 
the  infusions  of  spent  tan,  being  first  placed  in  the  weak- 
est. During  their  sojourn  in  these,  they  are  taken  out 
every  morning  and  evening,  and  allowed  to  drain  over 
the  vats  during  three  hours.  Towards  the  end  of  the 
proceeding,  when  in  the  stronger  infusions,  a  removal 
from  the  vats  once  a  day  is  sufficient. 

The  baths  of  the  English  tanners  have  less  acidity 
than  those  employed  in  France,  as  they  use  infusions  of 
fresh  bark  in  clear  water.  They  work  with  a  large  num- 
ber of  baths,  increasing  gradually  in  strength ;  and  with 
vats  of  sufficient  capacity  for  fifteen  or  twenty  skins. 

The  best  of  all  the  methods  originally  used  for  this 
purpose  in  France,  is  that  described  by  Delalande  as  the 
one  long  pursued  at  St.  Germain.  In  this  process,  a 
series  of  twelve  infusions  is  used,  of  which  the  ten  first 
consist  of  old  infusions  of  tan,  which  had  been  before 
used,  and  the  two  last  of  fresh  tan-liquor.  The  skins, 
a  dozen  of  which  are  operated  on  at  a  time,  when  scraped 
and  washed,  are  deposited  in  the  first  or  weakest  bath, 
made  only  slightly  sour;  are  taken  from  it  at  the  end  of 
twenty-four  hours,  and  after  being  allowed  to  drain 
during  half  an  hour,  are  deposited  in  the  next  stronger 
infusion  of  the  series,  and  so  on,  being  changed  every 
day  until  they  have  been  treated  in  the  tenth  vat,  or  the 
last  of  the  old  tan-liquors.  The  eleventh  infusion,  or  the 
first  of  the  fresh  tan-liquors,  consists  of  sour  liquor,  to 
which  twenty-two  pounds  of  coarse  tan  have  been  added 
for  each  skin  to  be  worked  in  it.  The  skins  remain  ten 
days  in  this  vat,  and  are  then  changed  to  the  twelfth  of 
the  series,  which  contains  the  same  proportionate  amount 
of  coarse  bark  as  the  other,  but  mixed  with  a  stronger 
liquor.    After  being  allowed  to  soak  for  ten  days  in  this, 


SWELLING,  OR  RAISING. 


195 


they  are  ready  for  the  tanning  proper,  and  are  removed 
at  once  to  the  pit.  An  elevated  temperature  is  very  in- 
jurious to  the  weakest  of  these  infusions,  and  when  the 
operation  is  conducted  in  summer,  care  should  be  taken 
to  exclude  the  heat  as  much  as  possible  from  the  room 
containing  the  vats. 

The  sour  liquor  of  the  manufactories  at  St.  Germain, 
was  prepared  in  the  following  manner :  Five  ordinary  vats 
were  made  use  of;  the  first,  which  we  will  call  No.  1, 
being  destined  for  the  weakest,  and  the  last,  or  No.  5,  for 
the  strongest  infusions.  The  spent  tan  from  the  pit  in 
which  skins  had  been  imbedded  for  the  third  time,  was 
deposited  in  No.  5,  and  warm  water  poured  upon  it 
through  a  pipe  or  spout.  The  water  filtering  through 
the  tan,  passed  into  a  draining-well,  and  was  pumped  out 
after  four  or  five  days,  constituting  then  an  amount  of 
tan  liquor,  sufiicient  for  four  of  the  ordinary  first  or  weak 
vats.  The  pit  was  again  filled  with  water,  which,  after 
becoming  tan  liquor,  was  transferred  into  the  vats  Nos.  1 
and  2,  and  the  contents  of  Nos.  3  and  4  were  composed 
of  the  liquor  of  Nos.  1  and  2,  again  passed  through  No. 
5,  and  the  infusion  originally  drawn  from  No.  5,  was  re- 
placed in  it.  The  eleventh  and  twelfth  vats  originally 
referred  to,  were  made  up  from  the  contents  of  No.  5,  and 
the  other  ten  from  the  contents  of  Nos.  3  and  4,  diluted 
in  the  proper  manner  with  those  of  Nos.  1  and  2.  The 
exhausted  and  dried  tan  was  used  for  fuel. 

The  following  method  is  that  now  pursued  in  France 
by  the  best  tanners:  The  skins,  after  being  carefully 
fleshed  and  deprived  of  all  superfluous  parts,  are  soaked 
for  twenty-four  hours  in  fresh  water.  When  perfectly 
clean  and  well  rinsed,  they  are  deposited  in  the  liquors 
by  which  they  are  to  be  deprived  of  hair  and  raised. 
These  are  contained  in  a  series  of  eight  or  ten  vats,  made 
of  oak,  hooped  with  iron,  and  each  one  being  three  feet 


196 


SWELLING,  OR  RAISING. 


eight  inches  in  depth,  and  five  feet  five  inches  in  diame- 
ter. Seven  or  eight  skins  are  deposited  in  vats  of  this 
size,  enough  liquid  being  poured  in  to  cover  them  com- 
pletely. The  skins  are  left  to  soak  for  twenty-four  hours 
in  the  first  vat,  which  contains  the  weakest  liquor,  and 
are  taken  out  twice  during  that  time  to  drain  for  an  hour; 
being  placed  for  that  purpose  on  boards  which  are  inclined 
so  that  the  fluid  dripping  from  them  runs  back  into  the 
vat.  On  the  second  day  they  are  taken  out,  left  to  drain 
for  an  hour,  and  are  then  placed  in  the  second  vat,  which 
contains  a  stronger  infusion;  and  the  same  series  of 
operations  is  repeated  daily,  until  the  skins  have  passed 
through  all  the  vats.  If,  at  the  end  of  this  time,  the  hair 
appears  ready  to  fall  off,  as  is  usually  the  case,  particu- 
larly in  warm  weather,  it  is  removed  from  the  skins  by 
working  them  in  the  ordinary  manner  upon  the  horse, 
with  the  dull  or  round  knife.  In  cold  weather  it  is  some- 
times the  case  that  the  process  has  not  been  sufficiently 
completed  at  the  end  of  the  time  mentioned,  and  that 
the  skins  require  exposure  to  the  strong  liquors  for  five 
or  ten  days  longer,  in  order  that  the  hair  may  be  re- 
moved from  them  with  ease. 

The  skins  thus  deprived  of  hair,  have  not  yet  been 
raised  sufficiently  to  prepare  them  for  the  tanning,  and 
for  this  purpose  must  be  exposed  to  the  influence  of  four 
more  vats  of  tan-liquor  gradually  increasing  in  strength. 
The  mode  of  doing  this  is  precisely  the  same  as  that  de- 
scribed above.  After  having  passed  through  these  four 
vats,  they  are  deposited  in  a  vat  of  the  size  before  men- 
tioned, nearly  full  of  strong,  fresh  tan-juice,  which  has 
been  previously  thoroughly  mixed  by  repeated  stirring, 
with  four  pounds  six  ounces  of  sulphuric  acid  at  65°. 
During  the  first  day  of  their  soaking  in  this  vat,  the 
skins  are  taken  out  twice,  and  left  to  drain  for  two  hours. 


SWELLING,  OR  RAISING. 


197 


On  the  second  day  they  are  removed  once,  being  al- 
lowed to  drain  the  same  length  of  time,  and  on  the 
morning  of  the  third  day,  they  are  changed  to  the  last 
raising  vat,  which  contains  the  strongest  tan-liquor  that 
can  be  procured,  previously  well  mixed  as  before,  with 
four  pounds  six  ounces  of  sulphuric  acid.  On  the  even- 
ing of  that  day  they  are  taken  out  to  drain  for  an  hour, 
and  are  replaced  in  the  vat;  and  the  next  day  and  day 
after  that,  are  again  taken  out,  exposed  to  drain  for  the 
same  length  of  time,  and  deposited  again  in  the  liquor. 
Three  hours  after  the  last  draining,  they  are  finally  re- 
moved and  are  then  found  to  be  properly  raised  and 
ready  for  tanning.  In  this,  as  in  the  preceding  processes, 
if  the  weather  is  so  cold  as  to  retard  the  raising,  the 
skins  may  be  kept  for  two  days  instead  of  one  in  each  of 
the  vats.  The  flesh  side  should  always  be  placed  up- 
wards in  the  vats. 

Quite  as  many  and  various  processes  for  treating  skins 
with  tan-liquor  have  been  devised,  as  for  the  use  of  bar- 
ley dressings,  but  we  will  content  ourselves  with  the 
description  of  two  which  seem  to  merit  notice. 

In  the  first  of  these,  three  vats  are  suflicient,  and  the 
skins  are  exposed  to  five  infusions.  The  first  is  weak, 
being  composed  of  four  bucketfuls  of  tan,  and  five  of 
water,  and  is  not  prepared  until  it  is  required  for  use. 
The  skins,  after  being  softened,  dipped,  and  rinsed,  are 
steeped  in  this  for  twenty-four  hours,  being  taken  out  to 
drain  for  a  quarter  of  an  hour,  three  times  during  the 
day.  They  are  then  deposited  and  treated  in  the  same 
manner  in  the  contents  of  the  second  vat,  which  has 
been  prepared  four  or  five  days  beforehand,  and  consist 
of  six  bucketfuls  of  tan,  mixed  with  one-fourth  of  tan- 
liquor  and  three-fourths  of  water.  On  the  third  day, 
they  are  placed  in  a  vat  containing  six  bucketfuls  of 


198 


SWELLING,  OR  RAISING. 


tan,  mixed  with  equal  parts  of  tan-liquor  and  water. 
At  the  end  of  two  days,  the  skins  are  then  put  to  soak 
in  a  liquor  composed  of  the  contents  of  the  last  vat, 
mixed  with  sour  liquor  from  the  draining-well.  They 
remain  for  five  days  in  this,  being  taken  out  and  drained 
as  before.  On  the  first  day,  40  pounds  of  coarse  bark, 
for  every  six  skins,  are  added  to  the  mixture ;  and,  on 
the  second,  third,  and  fourth  days,  22  pounds  for  the 
same  number,  are  mixed  with  it ;  the  skins  being  only 
removed  to  drain  twice  on  the  fourth  day.  On  the  fifth 
day,  they  are  taken  out  once  to  drain  for  a  quarter  of 
an  hour,  are  replaced,  and  well  powdered  over  with 
about  40  pounds  of  coarse  bark  for  every  six  skins. 
After  being  left  in  this  mixture  for  eight  or  nine  hours, 
they  are  removed,  and  placed  in  the  fifth  and  last  liquor, 
which  consists  of  a  mixture  of  strong,  fresh  infusion,  and 
of  sour  liquor.  They  are  left  in  this  for  three  days, 
being  taken  out  to  drain  each  morning  and  evening,  and 
12  pounds  of  coarse  bark  being  thrown  in  every  day. 
On  the  morning  of  the  fourth  day,  they  are  taken  out 
and  drained  for  three-quarters  of  an  hour,  during  which 
time  the  liquor  is  well  stirred  by  workmen ;  after  which, 
they  are  returned  to  the  vat,  a  large  quantity  of  spent 
or  coarse  bark  being  thrown  upon  each  skin  as  it  is  put 
in.  The  skins  remain  in  this  state  eight  days,  when 
this  part  of  the  process  is  concluded. 

When  the  skins  have  been  taken  from  the  first  vat, 
its  contents,  being  very  weak  and  exhausted,  may  be 
thrown  away;  and  the  second  infusion,  when  used,  may 
be  poured  into  it  to  supply  its  place  for  another  opera- 
tion; and  so  on  to  the  last  vat,  the  contents  of  the 
stronger  one  being  poured,  when  once  used,  into  the  vat 
next  behind  it  in  the  series. 

The  other  method  of  treating  skins  with  tan-liquor 


SWELLING,  OR  RAISING. 


199 


has  already  been  partially  described  in  the  account  of 
that  pursued  at  St.  Germains.  In  most  tanneries,  a 
series  of  eight  vats  is  used  in  summer,  and  one  of  twelve 
in  winter ;  in  the  first  case,  the  weakest  infusion,  con- 
sisting of  one  part  of  strong  tan-liquor  to  seven  of  water ; 
the  next  strongest,  of  two  of  liquor  and  six  of  water; 
and  so  on  to  the  eighth,  which  consists  of  tan-juice 
unmixed. 

In  spring  and  in  autumn  the  skins  are  made  to  pass 
through  ten  vats,  the  first  containing  one  part  of  liquor 
and  nine  of  water,  and  the  last,  the  strong  infusion.  In 
winter,  the  weakest  consists  of  one  part  of  liquor  to 
eleven  of  water,  and  so  on.  In  summer,  the  skins  are 
taken  out  and  left  to  drain,  during  an  hour,  twice  a  day, 
on  the  first  three  days;  and,  in  winter,  as  often  on  the 
first  five  days.  Until  the  seventh  day  in  summer  and 
the  eleventh  in  winter,  they  are  taken  out  daily,  to 
drain  for  two  hours;  and  at  the  end  of  the  seventh  day 
in  summer,  and  the  eleventh  in  winter,  they  are  re- 
moved, left  to  drain  during  two  or  three  hours,  and  are 
then  replaced  in  the  vat,  each  skin  being  liberally 
sprinkled  with  coarse  tan.  They  remain,  for  three  or 
four  days  without  being  disturbed,  in  the  vats,  which,  in 
either  case,  are  the  next  to  the  last,  and  are  then  re- 
moved to  the  last  vats,  which  contain  undiluted  tan- 
liquor;  and,  after  being  steeped  in  them  for  six  or  eight 
days,  are  ready  to  be  transferred  to  the  pits.  As  cold 
retards  or  prevents  the  fermentation  of  the  materials 
and  the  success  of  the  process,  the  time  of  exposure  may 
be  still  further  extended  in  winter,  or  the  contents  of 
the  vats  may  be  kept  moderately  w^arm  by  the  aid  of 
artificial  heat. 

Many  other  slight  variations  from  these  processes  have 
been  resorted  to  by  difierent  manufacturers.    But  since 


200 


SWELLING,  OR  RAISING. 


the  quantity  of  acid  necessary  to  raise  the  skins  has 
been  determined  by  Seguin,  the  most  important  opera- 
tions of  the  method  by  tan-liquor  have  been  conducted 
with  uniformity.  The  adherents  of  the  old  modes  of 
separating  hair  and  raising  skins  have  opposed  many 
objections  to  these  processes,  on  account  of  their  diffi- 
culty, and  the  care  and  nice  management  required  in 
their  use ;  but  there  can  be  no  doubt  of  their  advantages, 
and  of  the  very  superior  quality  of  the  leather  manu- 
factured by  them. 

Preparatio7i  of  the  Tan-liquor. — The  tan-liquors  used 
in  the  processes  we  have  been  describing,  are  obtained 
by  the  filtration  of  water  through  the  partially  exhausted 
bark  of  the  second  and  third  series  of  vats  in  the  tan- 
yard,  and  derive  from  it  their  astringent  and  acid  pro- 
perties. This  tan,  after  remaining  for  a  time  in  contact 
with  the  skins  in  the  vat,  loses  and  gives  up  to  them 
the  greater  portion  of  its  tanning  ingredients,  and  then 
is  readily  disposed  to  ferment  and  acidify;  still  retaining, 
however,  some  of  its  tanning  properties,  but  becoming 
more  and  more  acid  as  these  are  removed  from  it  by 
absorption  into  the  tissues  of  the  skins.  These  qualities 
are  calculated  to  injure  the  leather,  and  make  its  re- 
moval from  the  vats  necessary  before  it  has  been  too 
long  exposed  to  the  action  of  the  exhausted  and  acidified 
tan. 

For  the  purpose  of  procuring  the  sour  liquor,  then,  the 
tan  from  the  second  or  third  series  of  pits,  from  which 
the  leather  has  been  removed,  is  deposited  in  an  empty 
vat,  in  which  a  draining-well,  or  chimney,  composed  of 
oak  planks  tightly  joined  together,  has  been  erected. 
Fig.  37.  This  well  is  so  arranged  that  the  fluid  can  only 
enter  it  from  below;  and  a  pump  adapted  to  it,  serves 
to  withdraw  its  contents;  or  they  may  be  removed  in  a 


STTELLING;  OR  RAISING. 


201 


bucket  (Fig.  38).  The  vat  is  then  filled  with  water, 
and  the  solution  formed  by  its  filtration  through  the 


tan,  is  raised,  after  a  few  days,  from  the  well,  and  is 
again  poured  over  the  surface.  This  proceeding  is  re- 
peated again  and  again,  until  the  tan  is  entirely  ex- 
hausted of  its  soluble  contents.  The  top  of  the  vat 
should  be  kept  closed,  so  as  to  prevent  loss  of  fluid  by 
evaporation.  In  place  of  this  method,  a  number  of  vats 
may  be  filled  with  the  spent  tan,  and  the  solution  taken 
from  one  of  the  series  may  be  made  to  pass  through  a 
second,  a  third,  or  more,  until  sufficiently  saturated. 
From  fifteen  days  to  a  month  are  usually  required  to 
give  the  liquors  the  proper  degree  of  strength  and 
acidity. 

The  mode  described  above  of  withdrawing  the  liquor 
from  the  pits,  is  much  the  most  convenient;  but  in  small 
establishments,  where  great  economy  is  practised,  a  vat 
may  be  kept  filled  with  tan  and  water  for  three  weeks, 
and  the  liquor  may  then  be  removed  by  making  a  hole  in 
the  centre  of  the  pit,  and  taking  out  the  fluid  collecting 
in  it,  with  a  bucket.  This  liquor  should  again  be  poured 
over  the  surface,  and  the  same  process  be  repeated,  until 
it  is  found  to  be  of  the  requisite  strength ;  when  it  may 
be  clarified  for  use,  by  pouring  it  through  a  close  wicker 
basket,  which  will  retain  the  floating  particles  of  tan. 
The  infusion  is  known  to  be  of  the  proper  strength, 


Fig.  37. 


Fig.  38. 


14 


202 


WORKING  ON  THE  BEAM. 


when  it  has  a  clear,  light-red  color,  and  a  taste  slightly 
less  acid  than  that  of  common  good  vinegar. 

After  the  tan  has  been  nearly  exhausted  by  the  solu- 
tion of  its  ingredients  in  the  first  liquor  obtained  from  it, 
fresh  water  may  be  repeatedly  passed  through  it  in  the 
same  way  as  before,  and  the  resulting  liquid  may  be  em- 
ployed either  alone,  for  the  weaker  baths,  or  for  mixing 
with  the  infusion  first  obtained. 

Raising  hij  Yeast. — Yeast,  like  other  substances  which 
pass  into  acetous  fermentation,  has  the  property  of  rais- 
ing skins,  and  has  been  used  for  the  purpose.  It  is  mixed 
in  a  vat  with  warm  water,  the  vat  is  covered,  and  fermen- 
tation takes  place.  When  this  is  fully  established,  a 
quantity  of  salt  is  thrown  in,  and  the  skins  are  deposited 
in  the  vat,  the  contents  of  which  are  then  treated  pre- 
cisely as  in  the  case  of  barley  dressings.  The  operation 
can  be  conducted  in  the  cold,  but  is  much  more  rapid 
and  successful  if  the  temperature  of  the  liquor  be  kept 
elevated."^ 


WORKING  ON  THE  BEAM. 

After  the  skins  have  been  prepared  for  the  separation 
of  the  hair  upon  them  by  any  one  of  the  numerous  me- 
thods which  have  been  described,  the  next  proceeding  is 

*  As  many  of  the  processes  for  swelling,  or  raising  the  hides,  de- 
scribed in  this  Chapter,  are  not  in  use  in  the  United  States,  a  nearly 
literal  translation  is  retained  of  the  parts  of  the  French  work  which 
contain  them,  along  with  the  editorial  "We,"  which,  as  in  some  other 
instances,  will  be  understood  from  the  context,  not  to  express  the  opin- 
ion of  the  American  editor.  These  and  other  parts  of  the  book  were 
translated,  before  the  necessity  of  the  numerous  changes  and  additions 
since  made  was  evident;  and  it  has  been  thought  proper  to  present  them 
in  their  original  form. 


WORKING  ON  THE  BEAM. 


203 


to  remove  it  entirely,  by  working  them  upon  the  beam. 
For  this  purpose  the  workman  makes  a  kind  of  pad  of 
two  or  three  folded  skins,  which  he  places  upon  the 
horse,  and  over  which  the  skin  to  be  operated  upon  is 
laid  with  the  hair  side  up;  and  he  then  scrapes  the  sur- 
face strongly  from  above  downwards,  with  the  scraper. 
After  the  hair  is  completely  removed,  the  skin  is  washed 
and  soaked  in  a  trough,  or  vat  full  of  water,  and  is  then 
subjected  to  the  following  operations : — 

1.  The  flesh  and  other  parts  not  properly  belonging 
to  the  skin,  are  removed  with  a  sharp  knife  called  the 
fleslier^  and  the  skin  is  again  washed  and  soaked  in  fresh 
water. 

2.  The  projecting  filaments  or  shreds,  and  those  parts 
of  the  borders  of  the  skin  which  are  thicker  than  the 
rest,  are  cut  off  with  a  sharp  knife,  and  the  skin  is  again 
immersed  in  fresh  water.  The  portions  thus  removed 
may  be  set  aside  for  the  use  of  manufacturers  of  glue. 

3.  The  hair  side  is  then  well  rubbed  and  smoothed 
down  with  a  stone,  similar  to  that  used  for  sharpening 
the  knife-blades,  but  which  is  set  in  a  wooden  handle. 
This  done,  the  skin  is  dipped  for  the  third  time  in  fresh 
water. 

4.  Both  sides  are  well  scraped  and  smoothed  with  a 
knife  having  a  curved  blade,  so  as  to  equalize  the  surfaces 
and  remove  all  foreign  particles. 

A  dozen  skins  can  be  worked  in  this  way  by  one  man 
in  the  course  of  a  day. 


CHAPTEK  XIV. 


TANNING  PROCESS. 

Having  completed  the  consideration  of  the  various 
operations  to  which  skins  are  subjected  before  they  are 
prepared  for  tanning,  we  proceed  to  give  an  account  of 
the  latter  process,  commencing  with  a  description  of  the 
pits  or  vats  in  which  it  is  conducted. 

TAN  VATS. 

Some  of  these  consist  of  large,  square  holes,  excavated 
in  the  ground,  about  six  and  a  half  feet  deep,  and  eight 
feet  across,  and  lined  with  masonrj  and  hydraulic 
cement. 

At  Paris,  and  many  other  places,  however,  they  con- 
sist of  strong  cylindrical,  open,  iron-bound,  oak-wood 
vats,  covered  externally  with  pitch,  and  sunk  into  the 
ground.  These  are  less  liable  to  leak  than  those  before 
mentioned;  and  not  having,  in  their  construction,  an}' 
lime  or  other  material  which,  by  chemical  action  upon 
the  tan  liquor  or  skins,  might  impair  the  quality  of  the 
leather,  are  far  superior  to  them.  These  advantages 
have  caused  their  general  adoption.  There  is,  however, 
another  form  of  vat,  recently  invented  and  patented  by 
T.  W.  Brown,  of  Virginia,  and  shown  in  perspective  by 
Fig.  39.    This  view  also  exhibits  the  movable  bark 


TAN  YATS.  205 

chamber  contained  in  the  vat;  the  hide  frame  and  wind- 
lass for  moving  them. 


Fig.  39. 


"Figure  40  is  a  perspective  view  of  a  locomotive  bark 
chamber  detached  from  the  vat.  Similar  letters  in  the 
figures  refer  to  corresponding  parts. 


Fig.  40. 


206 


TAN  YATS. 


"  The  invention  and  improvement  consist  in  the  em- 
ployment of  a  rectangular  chamber  A^  for  containing  the 
bark,  mounted  upon  four  wheels  B,  by  which  it  is  moved 
to  and  from  the  vat,  and  provided  with  two  loops  c,  to 
receive  the  hooks  d  of  the  windlass  chain  for  raising 
and  lowering  the  said  bark  chamber  A  in  the  vat,  one 
side  and  the  bottom  containing  a  number  of  parallel 
slits  a,  to  allow  the  liquor  to  run  through,  and  not  the 
bark;  the  use  of  the  said  rising  and  falling,  and  locomo- 
tive chamber  A,  in  combination  with  the  ordinarj^  vat  f, 
affording  to  the  tanner  a  convenient  mode  of  managing 
the  bark,  and  enabling  him  to  extract  the  greatest  amount 
of  tanning  properties  from  it,  and  to  draw  and  handle 
the  bark  as  well  as  the  hides,  which  is  a  very  important 
part  of  the  tanning  process,  and  to  empty  and  supply 
the  vat  of  bark  with  great  facility,  the  wheels  not  only 
serving  to  facilitate  the  operation  of  transportation  of  the 
bark  chamber,  but  to  prevent  its  bottom  from  touching 
the  bottom  of  the  main  vat  f,  when  lowered  into  it,  and 
then  allowing  a  free  passage  for  the  liquor  to  circulate, 
and  the  slits  in  the  side  and  bottom  of  the  bark  cham- 
ber permitting  the  liquor  to  run  freely  through  the  bark 
and  out  of  the  chamber  as  the  latter  is  raised ;  and  again 
to  run  into  it  and  to  circulate  through  the  bark  when  the 
chamber  is  again  lowered  into  the  vat  f;  and  by  a  repe- 
tition of  these  operations,  to  extract  the  tanning  proper- 
ties from  the  bark  most  effectually;  this  mode  of  handling 
the  bark  in  the  process  of  tanning  leather  being  entirely 
new,  the  bark  heretofore  having  remained  at  the  bottom 
of  the  vat  in  a  compact  mass,  preventing  a  change  in 
its  position  and  a  free  circulation  of  the  water,  and  con- 
sequently a  proper  extraction  of  the  tanning  properties 
from  the  bark,  and  much  difficulty  in  removing  it  whilst 
changing  the  bark.    The  strongest  liquor  would  also  re- 


TAN  VATS. 


207 


main  at  the  bottom  of  the  vat.  My  improved  bark 
chamber  will  permit  the  strongest  liquor  to  percolate 
through  the  bark  and  bottom  of  the  chamber,  and  pass 
thence  into  the  part  of  the  vat  containing  the  hides, 
and  when  the  chamber  is  raised  to  a  higher  level,  the 
liquor  will  pass  into  the  vat  amongst  the  hides,  at  a 
higher  level." 

"The  hides  h  are  suspended  to  a  rising  and  falling 
frame  i,  placed  in  the  same  vat  that  receives  the  afore- 
said chamber,  being  raised  and  lowered  by  the  same  wind- 
lass L  that  raises  and  lowers  the  bark  chamber,  k  is  the 
frame  that  sustains  the  windlass,  l  is  the  windlass,  m 
are  the  bearings  in  the  frame  to  receive  the  windlass 
when  the  latter  is  applied  to  the  raising  and  lowering  of 
the  bark  chamber." 

In  the  common  vats,  after  the  skins  have  undergone 
all  the  preparatory  processes,  they  are  cut  in  half  and 
stratified  along  with  tan  in  the  following  manner: — 

The  bottom  of  the  vat  is  first  covered  to  the  height 
of  six  or  seven  inches  with  spent  bark,  and  over  this 
substratum,  a  layer  of  fresh  bark,  an  inch  or  more  thick, 
and  well  moistened  and  pressed  down,  is  spread.  A  skin 
is  then  placed  on  top  of  this  layer  of  bark,  then  another 
stratum  of  fresh  bark,  and  so  on,  alternately  a  skin  and 
bark  until  the  vat  is  full. 

Each  intervening  stratum  of  bark  must  be  an  inch 
deep,  and  always  moistened  like  the  first;  and  it  should 
be  equally  spread  over  the  surface  of  the  hide. 

Many  tanners  use  the  dry  powder  as  it  comes  from 
the  mill,  but  it  is  worked  with  much  difiiculty  when  in 
that  state,  and  the  laborers  are  exposed  to  the  danger  of 
inhaling  the  dust  which  is  constantly  rising  from  it.  A 
much  safer  and  more  convenient  method  is  to  moisten  it 
outside  of  the  vats,  as,  when  in  the  humid  state,  it  may 


208 


TAN  VATS. 


with  great  ease  be  thrown  upon  the  skins  and  spread 
out  upon  them  with  a  shovel. 

When  the  skins  have  all  been  imbedded  in  the  tan, 
they  are  to  be  covered  with  a  six  inch  stratum  of  bark, 
technically  termed  the  hat,  which  must  be  distributed 
uniformly  over  the  surface,  pressed  down  by  the  feet, 
and  covered  with  boards. 

In  small  tanneries  the  pits  are  not  always  filled  on  the 
same  day,  and  frequently  only  a  small  number  of  hides 
are  placed  in  them  at  a  time.  As  it  is  essential  in  these 
cases  that  they  should  be  kept  fully  moistened,  more 
water  should  be  added  each  time  that  the  new  skins  are 
deposited  in  them ;  and  in  order  that  the  relative  position 
of  the  contents  may  not  be  disturbed,  the  surface  should 
be  covered  with  a  coarse  cloth,  and  the  water  carefully 
poured  over  from  a  watering  pot,  and  allowed  to  infil- 
trate gradually. 

The  water  being  equally  distributed  throughout,  and 
in  sufficient  quantity,  the  liattwg  of  the  pit  is  com- 
pleted. In  establishments  where  they  do  not  commence 
vatting  until  a  number  of  hides  sufficient  to  fill  the  vats 
has  been  prepared,  the  watering  should  be  completed  in 
one  operation.  When  this  is  the  case,  it  may  happen 
that  the  tan  rapidly  absorbs  all  the  water  poured  in,  and 
in  a  day  or  two  appears  to  have  become  perfectly  dry. 
More  water  should  then  be  added,  until  it  is  certain  that 
the  vat  contains  enough  to  moisten  thoroughly  all  the 
hides.  The  quantity  required  for  each  hide  is  about  12 
gallons. 

When,  as  often  happens,  particularly  in  small  esta- 
blishments, the  tanner  is  compelled  to  place  together  in 
the  same  vat,  hides  in  different  states  of  progress,  that 
is,  those  of  the  first,  second,  and  third  treatment,  the 
following  mode  of  arranging  them  must  be  resorted  to. 
Those  of  the  third  treatment  are  to  be  deposited  at  the 


TAN  VATS. 


209 


bottom;  those  of  the  second,  above  them  in  the  middle; 
and  those  of  the  first  on  top;  so  that,  when  those  which 
have  gone  through  the  three  treatments  are  taken  out  to 
dry,  those  of  the  second  may  occupy  their  place  at  the 
bottom,  those  which  were  before  at  the  surface  being  in 
the  middle,  and  the  fresh  hides,  which  are  to  be  sub- 
jected to  their  first  treatment,  being  placed  at  the  top. 
This  convenient  method  promotes  an  equalization  of  the 
tanning,  and  should  always  be  adopted;  because  the  con- 
tinued exposure  of  the  same  set  of  hides  to  those  parts 
of  the  vat  which  possess  the  greatest  tanning  power,  and 
of  others  to  the  upper  strata  of  bark  which  contain  the 
least,  is  thus  avoided.  The  substances  at  the  bottom 
of  the  vat,  undoubtedly,  are  those  which  possess  the 
strongest  tanning  powers,  because  the  descending  in- 
fusion, passing  through  the  layers  of  tan  above,  becomes 
more  fully  impregnated  with  tannin  and  extractive  mat- 
ter than  that  portion  which  remains  in  contact  with  the 
upper  strata  of  solid  materials.  Moreover,  the  complete 
penetration  and  combination  of  these  matters  with  the 
fibrine  and  gelatine  of  the  skins  is  promoted  by  the 
pressure  of  the  superincumbent  hides,  the  tan,  and  the 
column  of  fluid. 

When  the  ordinary  arrangement  is  adopted,  it  is  cus- 
tomary in  filling  the  second  vat,  to  place  at  its  bottom 
those  hides  which  have  been  at  the  top  of  the  first,  and 
so  on  throughout  the  ranges  of  vats.  This  is  done  for 
the  purpose  of  promoting  a  uniform  impregnation  of  all 
the  hides;  since,  if  always  kept  in  the  same  position  in 
their  progress  through  the  yard,  those  occupying  the 
lowest  one  would  be  the  most  thoroughly  charged  with 
tannin. 

As  oak  bark  is  variable  in  quality,  it  is  scarcely  possi- 
ble to  give,  with  certainty,  any  proportion  which  it  should 


210 


TAN  VATS. 


bear  to  the  skins.  Skins  weighing  110  pounds  usually 
require,  however,  about  double  that  amount  of  bark. 
From  33  to  44  pounds  usually  suffice  for  each  of  the 
skins  from  Brescia,  which  do  not  commonly  weigh  more 
than  26  pounds.  Weak,  thin  and  poor,  or  dry  hides, 
being  of  inferior  quality,  require  very  little  bark,  and 
scarcely  acquire  any  increase  of  substance.  Common 
hides  scarcely  ever  need  exposure  to  more  than  three 
treatments ;  the  first  being  given  upon  the  grain,  and  the 
others  upon  the  flesh  sides.  The  finest  powder  is  used 
for  the  first  process,  which  should  occupy  three  months. 
Coarser  stufl"  is  employed  for  the  second,  which  should 
take  four  months,  while  the  coarse  harh  alone  is  sufficient 
for  the  third  exposure,  occupying  five  months.  This 
length  of  time  may  be  considered  sufficient  for  tanning, 
though  the  best  tanners  extend  it,  giving  to  their  hides 
four,  or,  for  the  best  qualities,  even  five  exposures  in  the 
pits. 

Fresh  hides,  of  course,  exhaust  the  tanning  ingredients 
to  which  they  are  exposed  in  the  first  process  much  more 
rapidly  than  they  do  in  the  subsequent  ones;  and  hence 
the  necessity  of  a  longer  treatment  in  the  second  and 
third  vats  than  in  the  first.  After  they  have  been 
thoroughly  fed  in  the  first,  further  contact  with  the  spent 
materials  would  be  useless,  as  these  are  almost  entirely 
deprived  of  activity;  and  it  may  be  very  injurious  to 
them  by  promoting  putrefaction.  In  passing  through 
the  last  vats,  however,  they  run  no  such  risk ;  for,  being 
in  contact  with  strong  solution  of  bark,  they  are  still 
constantly — though  from  the  resistance  of  their  already 
tanned  surfaces,  gradually — absorbing  tannin,  and  acquir- 
ing density.  Small  portions  of  alum  are  added  to  the 
tan  by  some  manufacturers,  with  the  intention  of  dimin- 
ishing the  impermeability  of  these  tanned  surfaces,  and 


TAN  VATS. 


211 


hastening  the  process  in  its  latter  stages.  The  practice 
is,  however,  neither  a  common  nor  a  desirable  one. 

In  changing  hides  from  one  pit  to  another,  care  should 
be  taken  to  remove  from  their  surfaces  all  the  spent  tan 
which  covers  them,  so  that  there  may  be  no  mixture  of 
effete  matter  with  the  fresh  bark.  Some  tanners  even 
take  the  trouble  of  beating  and  shaking  the  hides  each 
time  that  they  are  changed. 

The  importance  of  discovering  some  process  which 
would  shorten  the  time  usually  occupied  in  tanning, 
without  injuring  the  beauty  and  durability  of  the  leather, 
and  which  would  also  diminish  the  expense  of  the  manu- 
facture by  substituting  some  less  costly  materials  for  oak- 
bark,  has  long  been  appreciated  by  chemists  and  practical 
men.  Among  others  who  have  devoted  much  attention 
to  this  subject  is  Seguin,  who,  acting  upon  his  opinion 
that  the  combination  of  tannin  with  the  gelatine  and 
fibrine  of  skins  might  be  much  accelerated  by  presenting 
it  to  them  in  a  liquid  and  concentrated  form,  succeeded 
in  greatly  shortening  the  time  required  for  tanning.  But 
experience  has  shown  that,  though  the  leather  prepared 
by  such  means  is,  to  all  appearances,  well  tanned,  it  does 
not  possess  the  requisite  qualities.  It  is  not  thoroughly 
and  uniformly  impregnated;  for,  while  the  outer  layers 
of  the  two  surfaces  combine  rapidly  with  tannin,  a  deposit 
of  gallic  acid  and  extractive  matter  forms  a  compact 
coating,  which  prevents  their  complete  penetration,  and 
renders  their  interior  inaccessible  to  the  liquid.  This 
leather  is  dry  and  by  no  means  durable,  its  interior  con- 
sisting of  untanned  hide.  An  account  will  be  given,  in 
its  proper  place,  of  the  processes  of  Seguin  and  his  fol- 
lowers. 

Experience  has  shown  that,  to  insure  the  perfection 
of  leather,  all  the  gelatine  and  fibrine  of  the  original 


212 


TAN  YATS. 


skins  must  be  made  to  combine  with  tannin ;  and  that 
this  combination  must  be  effected  in  the  most  gradual 
way^  the  accomplishment  of  which  is  only  to  be  procured 
by  exposure  to  solutions  which  at  first  are  weak,  and 
afterwards  are  increased  in  strength,  until  at  last  com- 
plete saturation  is  arrived  at.  After  this  entire  conver- 
sion of  substance  has  been  attained,  further  exposure 
only  serves  to  injure  the  texture  of  the  hides  by  intro- 
ducing into  it  a  dry,  hard,  and  horny  matter,  which 
renders  them  brittle,  and  easily  penetrable  by  moisture, 
and  to  consume  uselessly  the  time  and  money  of  the 
manufacturer.  If,  on  the  contrary,  they  have  been  ex- 
posed too  short  a  time,  they  will  be  imperfect  and  want- 
ing in  the  requisite  weight  and  solidity.  It  is,  therefore, 
an  established  fact  that  twelve  or  eighteen  months  are 
required  for  the  complete  tanning  of  the  best  qualities 
of  hides,  they  being  found  to  increase  in  strength  and 
weight  up  to  the  end  of  that  time,  which  is  the  usual 
duration  of  the  process  in  England  as  well  as  in  this 
country.  Still,  there  as  well  as  here,  skins  are  often 
sent  into  the  market  after  an  exposure  of  six  or  ten 
months,  or  even  less  time. 

Dessabless  Process. — Dessables  reports  the  following 
process — which  we  give  in  his  own  words,  without  in- 
dorsing his  views — as  being  one  which  much  shortens 
the  length  of  time  required  in  tanning. 

"A  draining-well  is  to  be  erected  in  one  corner  of  the 
pit,  by  means  of  two  planks  properly  adjusted,  and  to 
this  a  pump  is  to  be  adapted.  The  liquid  which  filters 
through  the  tan  will  then  accumulate  in  the  well,  and 
can  be  distributed  over  the  surface  of  the  pit  two  or 
three  times  a  week,  by  means  of  the  pump.  These  re- 
peated washings  will  be  a  certain  means  of  extracting 
from  the  tan  all  its  soluble  parts,  and  of  keeping  the 


HERAPATH  AND  COX'S  PROCESS. 


213 


hides  always  soft,  and  in  a  condition  to  be  thoroughly 
moistened  and  penetrated  in  every  direction.  The  pro- 
per time  for  discontinuing  these  filtrations  and  refiltra- 
tions  can  be  easily  ascertained,  and  is  doubtless  much 
earlier  than  in  the  ordinary  methods." 

It  is  supposed  by  some  that  alum  would  assist  in  ren- 
dering leather  more  firm  and  durable,  and  that  if  any 
substance  as  astringent  as  it  is,  and  cheaper  than  oak- 
bark,  could  be  obtained,  the  time  taken  up  by  the  tan- 
ning process  would  be  much  abridged.  This  substance, 
however,  is  not  sufficiently  cheap  to  be  used  in  large 
quantities,  and  experience  has  not  yet  shown  that  it  pos- 
sesses the  properties  attributed  to  it. 

Herapath  and  Coxs  Process, — Herapath  and  Cox,  of 
England,  have  devised  a  quick  process  of  tanning,  which 
consists  in  passing  the  hides  between  two  horizontal  rol- 
lers, driven  by  steam,  once  or  twice  daily,  while  being 
handled  in  the  tan  vats.  This  treatment  expresses  the 
spent  liquor,  which,  if  allowed  to  remain  in  the  hide  after 
having  become  exhausted  by  it,  w^ould  impede  the  tan- 
ning power  of  fresh  ooze.  The  action  of  the  rollers, 
therefore,  in  the  intervals  between  the  usual  transfers 
from  the  weaker  to  the  stronger  vats,  by  driving  out  the 
impoverished  liquor,  predisposes  the  hides  to  a  more  rapid 
and  thorough  absorption  of  tannin  than  could  possibly 
be  the  case  if  they  were  passed  from  one  vat  to  another 
while  saturated  with  exhausted  liquor. 

The  lower  roller  should  be  about  thirty  inches  in 
diameter,  and  covered  with  hair  cloth;  and  the  upper  one 
only  eighteen  inches,  and  with  a  woollen  envelop.  The 
pressure  must  be  moderate,  else  the  quality  of  the  lea- 
ther will  be  impaired  by  too  great  condensation  of  the 
tissue.  The  hides  are  strung  together  with  twine,  and 
drawn  through  continuously. 


214 


HERAPATH  AND  COX'S  PROCESS. 


Butts  may  be  tanned  by  this  method  in  four  months, 
and  kips  and  skins  in  as  many  weeks. 

The  skins  must  be  connected  together  butt  to  butt 
and  shoulder  to  shoulder,  as  shown  in  Fig.  41. 


Fig.  41. 


Fig.  42. 


"One  end  of  the  band  of  skins  is  passed  between  the 
two  rollers  a  and  h  of  the  tanning  apparatus.  (Figs.  42 
and  43  •  Fig.  42  being  a  section  and  Fig.  43  a  front  view 

Fig.  43. 


of  the  apparatus.)  The  end  having  been  passed  between 
the  rollers,  it  is  to  be  attached  to  the  other  end  of  the  band 


CROP  LEATHER. 


215 


of  skins,  and  thus  forms  an  endless  band.  Rotary  motion 
is  then  communicated  to  the  apparatus  from  a  steam- 
engine,  by  means  of  the  drum  c,  which  is  mounted  on 
the  axle  of  the  roller  h.  A  small  pinion  d  is  also  mounted 
on  the  same  axle,  and  takes  into  a  toothed-wheel  e  on 
the  axis  of  the  lower  roller  a.  Upon  actuating  the  ap- 
paratus, the  skins  (which  have  been  previously  arranged 
in  the  tan  pit)  are  passed  between  the  two  rollers,  the 
upper  one  of  which  is  weighted.  The  exhausted,  or 
partially  exhausted  tanning  liquor  thereby  becomes  ex- 
pressed; and,  w^hen  the  skin  passes  onward  from  the 
rollers,  it  again  enters  the  pit  and  absorbs  a  quantity  of 
fresh  tannin." 

CROP  LEATHER. 

The  name  is  applied  to  leather  made  from  the  skins 
of  cows  or  small  oxen ;  the  former  being  very  eligible  for 
the  purpose,  provided  they  possess  sufficient  thickness, 
as  their  tissue  is  more  compact  than  that  of  ox-hides; 
at  least,  if  they  have  not  already  calved.  The  skins  of 
young  oxen  are  deficient  in  firmness  and  thickness,  and 
are  only  used  for  conversion  into  belt  leather. 

This  sort  of  leather  requires  a  much  more  thorough 
currying  than  thick  hides,  which  are  almost  fit  for  use 
when  taken  from  the  tanning.  It  is  employed  princi- 
pally by  shoemakers  for  second  soles,  and  uppers  for 
women's  shoes  and  men's  light  shoes  and  pumps.  Young 
ox-hides  are  regarded  by  shoemakers  as  inferior  to  cow- 
skins,  and  they  use  the  latter  for  the  upper  and  thin 
soles.  The  tanning  of  these  hides  is  conducted  in  a 
somewhat  different  way  from  that  of  thick  hides. 

They  are  placed  first  in  the  lime-pits,  and,  when  ready 
for  depilation,  which  is  usually  in  eight  days  during 
summer,  and  ten  or  twelve  in  winter,  are  repeatedly 


216 


CROP  LEATHER. 


fleshed  and  scraped,  care  being  taken  to  rinse  them  each 
time;  in  clean  and  running  water  if  possible,  so  as  to  re- 
move all  the  lime.  Those  intended  for  uppers  require 
at  least  four  or  five  rinsings,  while  two  will  suffice  for 
those  which  are  to  be  used  as  soles. 

They  are  then  deposited  in  wooden  vats,  four  feet  four 
inches  in  height  and  six  feet  and  a  half  wide,  which  are 
nearly  two-thirds  filled  with  a  weak  ooze  or  infusion  of 
oak-bark,  and  are  handled  daily. 

If  the  hides  are  worked  in  the  same  vat,  the  strength 
of  the  ooze  must  be  restored,  as  rapidly  as  exhausted,  by 
fresh  additions  of  bark.  When  transferred  to  other  vats, 
the  liquor  in  them  must  be  made  successively  stronger 
and  stronger. 

Tanners  usually  give  the  preference  to  this  method, 
but  skins  are  sometimes  treated  in  hot  ooze,  prepared  in 
vats  similar  to  those  just  described,  by  adding  hot  water 
to  bark,  which  is  used  in  the  proportion  of  five  basket- 
fuls  for  every  twenty-four  cow-skins.  After  being  placed 
in  the  vats,  the  skins  are  repeatedly  handled  or  moved 
about  by  the  workmen.  This  working  is  frequently 
repeated,  the  skins  being  taken  out  daily  to  drain,  and  a 
little  fresh  bark  being  added  to  the  vats  in  the  interval. 
This  manipulation  is  continued  for  four  to  six  weeks. 

Whichever  of  these  methods  is  adopted,  the  hides  are 
next  subjected  to  a  mixture  of  ground  bark  and  strong 
liquor  in  other  vats.  For  this  purpose,  the  bottom  of 
the  vat  is  covered  with  a  layer  of  fresh  tan,  carefully 
moistened,  upon  which  a  skin  is  spread  out  to  its  full 
extent;  this  is  covered  with  another  layer  of  tan,  and 
the  hides  and  bark  are  packed  in  alternately,  till  the  vat 
is  full.  The  top  hide  must  have  a  '^hat"  of  bark,  and 
the  contents  of  the  vat  be  then  drenched  with  ooze. 

The  workman  should  be  careful  to  place  the  skins  in 
every  direction  around  the  pit,  the  lengths  of  the  con- 


CROP  LEATHER. 


217 


tiguous  ones  forming  slight  angles  with  each  other,  and 
to  deposit  tan  in  all  the  creases  and  doublings  made  by 
the  bending  of  the  edges.  This  process  usually  requires 
six  weeks.  Five  baskets  of  tan  are  used  for  a  dozen 
ordinary  cow-skins,  and  about  six  for  six  dozen  young 
ox-hides.  The  skins,  having  undergone  this  preparation, 
are  then  further  exposed  to  two  treatments  in  the  vats 
in  precisely  the  same  manner.  After  remaining  in  the 
first  pit  for  three  months,  they  are  taken  out,  and,  before 
being  transferred  to  the  second  one,  are  beaten  or  trod 
out  for  the  purpose  of  rendering  them  more  supple. 
This  process — which  should  never  be  omitted  in  the 
case  of  skins  intended  for  shoemakers  and  saddlers — 
having  been  completed,  they  are  placed  in  the  second 
and  last  pit.  Tanners  disagree  about  the  time  proper  to 
be  consumed  in  this  final  exposure,  some  being  content 
with  five  weeks,  others  extending  it  to  three  months. 
The  latter  period  is  certainly  not  too  long  for  hides  which 
are  intended  for  leather  of  the  best  quality. 

After  withdrawal  from  the  pits,  the  leather  is  dried  in 
the  usual  manner,  care  being  taken  to  avoid  exposure  to 
the  sun,  a  strong  wind,  or  a  cool  and  damp  atmosphere, 
in  which  they  might  mould.  They  are  then  to  be  trans- 
ferred to  the  currier,  who  prepares  them  according  to 
the  kind  and  quality  of  the  leather,  and  the  purposes 
for  which  it  is  intended. 

Cow-skins  differ  very  much  in  quality ;  those  of  the 
younger  animals  being  much  superior  to  those  of  cows 
which  have  frequently  calved ;  the  latter  having  become 
weak  and  thin  by  the  distension  to  which  they  have  been 
subjected.  Young  ox-skins,  although  long  regarded  as 
inferior  to  the  better  kind  of  cow-skins,  are  equally  ser- 
viceable, and  the  two  are  now  used  indifferently  by 
shoemakers.  A  distinction  is,  however,  made  between 
15 


218 


CROP  LEATHER. 


the  bellies  of  the  former  and  some  of  the  other  parts  which 
are  weaker,  and  are  only  used  by  them  for  upper  soles. 

The  process  of  tanning  which  we  have  described,  is 
the  one  employed  in  all  the  best  establishments  in  Paris, 
but  there  are  some  Provincial  tanners  who  vary  it  more 
or  less.  According  to  Dessables  and  Delalande,  crop 
leather  is  made  in  Brittany,  by  the  process  of  tanning 
in  sacks,  hereafter  to  be  described.  After  having  been 
exposed  in  the  lime-pits  for  two  months,  and  placed  for 
seven  or  eight  days  in  hot  ooze  and  water,  they  are  then 
filled  with  the  decoction,  and  left  for  a  week  or  more, 
care  being  taken  to  change  their  position  five  or  six  times 
daily.  They  are  then  unripped,  placed  between  layers 
of  bark,  and  allowed  to  remain  untouched  during  eight 
days  before  being  taken  out  and  finally  dried. 

In  Limousin,  skins  are  limed  for  four  days,  and  are 
then  placed  in  the  tan-pits,  in  which  they  are  allowed  to 
remain  for  three  months. 

In  Dauphiny,  they  are  limed  for  a  fortnight,  then  ex- 
posed for  four  weeks  to  two  different  treatments  with 
bark,  and  transferred  to  the  vats,  where  they  remain  for 
a  month  and  a  half 

At  Metz  and  Yerdun,  after  having  lain  for  eight  days 
in  old  lime-pits,  and  as  much  longer  in  fresh  ones,  they 
are  exposed  to  the  action  of  ooze  for  a  month,  and  sub- 
sequently to  two  stratifications  with  tan  for  five  months 
longer. 

At  Bourges,  and  in  different  places  in  Berry,  they  are 
allowed  to  remain  three  months  in  the  lime-pits  and  six 
months  in  the  tan-vats. 

Lastly,  at  St.  Germain,  cow  and  calf  skins  are  passed 
through  three  old  lime-pits  and  one  fresh  one,  and  then 
undergo  five  cleanings  and  rinsings.  They  are  then 
beamed  and  relieved  with  the  knife  of  all  superfluities, 


DRYING  OF  LEATHER. 


219 


and  worked  upon  the  hair  side  with  a  whetstone,  and 
wdien  thus  w^ell  softened  and  cleaned,  are  again  thrown 
into  water.  After  being  worked  for  the  third  time  upon 
the  horse  with  the  round  knife  on  both  sides,  so  as  to 
expel  the  last  portions  of  lime,  they  are  again  rinsed ;  and 
a  fourth  and  fifth  time  treated  in  the  same  way.  The 
final  rinse  water  should  come  from  them  perfectly  clear, 
and  leave  them  in  a  proper  state  for  the  ooze  bath. 

Drying. — The  drying  of  leather,  however  simple  a  pro- 
cess it  may  appear,  is  one  which  requires  the  utmost 
skill  and  attention  on  the  part  of  the  w^orkmen,  and  the 
nicest  determination  of  the  point  to  which  it  should  be 
carried.  Skins  dried  too  slowly  and  in  moist  situations, 
are  liable  to  mould,  which  is  greatly  to  their  injury,  while 
those  which  are  dried  too  rapidly,  or  during  exposure  to 
the  direct  rays  of  the  sun,  become  hard  and  brittle. 

In  order  to  prevent  either  of  these  extremes,  every 
manufactory  should  have  attached  to  it  a  drying-room, 
proportioned  to  its  wants,  in  which  numerous  openings 
or  windows  admit  a  free  current  of  air,  while  the  leather 
is  protected  from  the  direct  influence  of  solar  heat. 

The  skins  when  sufficiently  tanned,  are  to  be  taken 
from  the  pits  without  being  shaken  or  beaten,  and  are  to 
be  stretched  on  pegs  or  hung  up  by  their  heads  from  large 
nails,  each  one  being  kept  expanded  by  two  or  three 
sticks,  passed  through  from  side  to  side,  so  that  all  parts 
may  be  uniformly  exposed  to  the  air.  '  When  they  have 
begun  to  whiten  and  have  become  slightly  stiff,  but  before 
they  are  perfectly  dry,  they  are  stretched  out  upon  a  clean 
place,  and  scoured  with  the  spent  tan  with  which  they 
are  still  covered.  When  well  cleaned  in  this  way,  they 
are  then  to  be  trod  out  and  beaten  with  the  soles  of  the 
feet  in  every  direction,  upon  both  sides ;  and  after  the 
inequalities  and  protuberances  of  surface  have  been  made 


220 


DRYING  OF  LEATHER. 


to  disappear  by  this  flattening  process,  they  are  assorted 
in  sizes  and  piled  in  uniform  heaps. 

"While  the  skins  are  stretched  in  the  drying-room,  they 
should  be  beaten  twice  daily,  at  morning  and  evening, 
upon  the  flesh  side,  with  a  round-faced  wooden  mallet. 
If  the  skins  should  be  dry,  the  operation  may  be  facili- 
tated by  moistening  their  surface  with  a  w^et  brush. 
This  process  imparts  firmness. 

After  the  skins  have  remained  in  piles  for  a  day,  they 
are  exposed  to  the  air  as  before  for  four  days.  When 
nearly  dry,  they  are  taken  down  and  pressed  under 
planks  heavily  weighted  with  large  stones.  The  next 
day  they  are  spread  out  upon  an  oak  or  marble  table  and 
beaten  with  an  iron  mallet  so  as  to  compress  their  tissue, 
and  render  them  smooth  and  compact.  (See  Fig.  44.) 


Fig.  44. 


This  proceeding  should  never  be  omitted,  whatever 
may  have  been  the  original  preparation  of  the  skins  for 
the  vats.  Limed  hides  should,  however,  be  treated  be- 
fore they  are  dry,  as  otherwise  the  hair  side  surface 
would  be  exposed  to  the  danger  of  being  broken  and 
rendered  uneven.  When  they  still  retain  a  little  moist- 
ure, this  cannot  occur. 

The  process  of  beating  leather  is  essential  to  give  it 
firmness  and  durability,  and  to  make  it  impervious  to 


BEATING  AND  ROLLING. 


221 


moisture.  It  is  only  the  first  step  of  the  manipulation 
which  the  shoemaker  finds  it  so  necessary  to  continue 
upon  the  lapstone. 

The  leather,  after  having  been  thus  hammered,  is  now 
thoroughly  dried  for  the  last  time,  and  piled  up  in  a  dry 
and  well-ventilated  loft.  Before  it  is  ready  for  market 
the  leather  should  be  repeatedly  shuffled,  as  it  were ;  that 
is,  the  position  of  each  hide  must  be  changed,  and  the 
piles  spread  out  in  the  manner  of  an  open  fan,  and 
pressed,  as  before,  under  planks  and  superincumbent 
weights. 

Having  undergone  these  different  processes  for  nearly  a 
month,  it  is  again  piled,  preparatory  to  being  sent  into  the 
market.  Not  content  with  this  management  of  it,  some 
tanners  even  take  the  unnecessary  trouble  of  storing  it 
away  in  cellars  for  some  time  before  they  consider  it 
thoroughly  seasoned. 

BEATING  AND  ROLLING. 

Leather  was  originally  beaten  with  hand-mallets,  a 
tedious  and  laborious  mode  of  operating,  which,  in  the 
course  of  time,  became  obsolete  by  the  invention  of  well- 
adapted  machinery.  The  chief  object  of  these  machines, 
at  first,  was  to  accelerate  the  process  and  diminish  the 
amount  of  labor ;  but  it  was  afterwards  found  that  they 
also  accomplished  the  desiderata  of  imparting  smooth- 
ness, compactness,  and  uniform  thickness  to  the  leather. 
Ignorance  of  their  real  usefulness  was  for  a  time  a 
serious  impediment  to  their  general  employment  by  the 
trade,  but  their  intrinsic  worth  soon  evinced  itself,  and 
they  are  now  regarded  as  indispensable  implements  of  a 
well-conducted  tannery. 

In  the  earlier  stages  of  this  invention,  the  imperfec- 


222 


BEATING  AND  ROLLING. 


tion  of  the  machinery  rendered  it  necessary,  very  fre- 
quently, to  finish  the  beating  by  hand,  in  order  to  im- 
part the  requisite  solidity;  but  improvement  grew  with 
experience,  and  has  resulted  in  some  comparatively 
perfect  apparatus. 

Sterlingue  and  Co.  were  the  pioneers  in  this  branch 
of  ingenuity,  and  proposed  the  use  of  a  hammer  like 
those  employed  for  forging  iron,  but  grooved ;  and  an 
anvil  faced  with  brass.  The  other  portions  of  their 
machine  are  a  table  for  receiving  the  hides,  and  cylinders 
for  the  cords  or  straps  which  keep  the  leather  extended, 
their  axes  being  connected  by  an  endless  chain,  in  such 
a  manner  that  the  straps  which  are  rolled  upon  them  on 
one  side  are  unrolled  on  the  other. 

The  hides  are  allowed  to  be  at  rest  during  the  descent 
of  the  hammer,  and  are  moved  from  under  it  during  its 
elevation.  The  blows  may  be  increased  in  frequency 
and  force  at  the  will  of  the  operator,  and  if  it  is  thought 
proper  to  direct  a  number  of  blows  upon  one  part  of  the 
hides,  the  movement  can  be  suspended  by  a  catch,  until 
the  required  number  has  been  applied.  By  these  means 
the  skin  is  uniformly  compressed  in  such  a  manner  as 
to  render  further  beating  by  hand  unnecessary. 

Having  found  that  the  horizontal  position  of  this 
hammer  interfered  somewhat  with  the  motion  of  the 
hides,  the  inventors  afterwards  substituted  a  vertical 
hammer  like  a  pile-driver,  which  they  patented  on  the 
6th  of  February,  1839.  By  this  improvement  they  have 
obtained  the  alternate  and  successive  action  of  a  number 
of  hammers  upon  the  leather,  and  established  a  system 
by  which  rows  of  hammers  of  moderate  weights  are  so 
arranged  that  those  of  the  second  row  descend  upon  the 
prolongation  of  a  line  oblique  to  that  of  the  first  one,  and 
fall  upon  the  hides  with  a  constantly  increasing  force. 


BEATING  AND  ROLLING. 


223 


Dehergue's  Maclivne, — This  machine,  invented  in  1840, 
is  described  in  vol.  Ivi.  p.  40,  plate  4,  of  French  reports 
of  expired  patents. 

Fig.  45. 


Figs.  45  and  46. 

a,  a.  Pulleys,  for  communicating  movement. 
h.  Longitudinal  iron  shaft. 

c,  c.  Cast  framework,  supporting  the  shafts  h  and  g. 

d,  Cast  support,  for  the  end  of  the  shaft  h, 

e,  e.  Pinions,  gearing  with  the  wheels  /,  /. 

g.  Iron-shaft,  carrying  the  wheels  /,  /,  outside  of  the 
framework. 

7i,  li.  Crank-rods,  the  iron  pivots  of  which,  ^,  i,  are 
fixed  by  means  of  nuts  in  grooves  cut  in  the  wheels  /,  /, 
60  that  their  position  can  be  changed  at  pleasure. 


224 


BEATING  AND  ROLLING. 


y.  Iron-shaft,  receiving  an  oscillating  motion  from  the 
cranks  h  and  7i. 

h.  Cast-iron  lever,  carrying  at  its  lower  extremity  a 
stamper  or  small  cylinder  in  a  fork,  and  having  passing 
across  it  the  shaft/,  the  movements  of  which  it  follows. 


Fig.  46. 


1  i  Q 

I  I 

The  upper  part  of  this  lever  is  equally  divided  into 
two  branches,  in  each  of  which  is  a  groove  traversed  by 
the  iron  shaft  fixed  at  its  extremities  to  double  cast 
supports  n  n.  Above  these  grooves  there  are  two  rests, 
o  0,  for  the  cast-iron  lever  which  pivots  upon  the  trun- 
nions q  q,  and  to  the  extremity  of  which  is  attached  an 
iron  rod  which  supports  a  cast  box  or  iron  plate,  or  else 
a  wooden  box  which  can  be  weighted  if  necessary.  Upon 


BEATING  AND  ROLLING. 


225 


the  line  marked  by  the  rests,  the  lever  can  be  moved 
over  the  whole  space  between  the  two  su23ports,  and  this 
part  should  be  accurately  adjusted,  so  that,  whatever 
may  be  its  position,  the  lever  will  weigh  uniformly  upon 
the  rests,  r.  Iron  shaft,  adjusted  between  the  two  sup- 
ports n  01,  and  resting  at  the  other  end  upon  a  simple 
support  s.  The  screw  passes  through  the  cast  piece  t, 
forming  its  nut,  and  having  two  projections  pierced  to 
receive  the  shaft  upon  which  it  moves  when  the  screw 
is  turned.  As  the  projections  of  the  nut  t  entirely  fill 
the  interval  between  the  branches  of  the  lever  Z:,  this 
lever  must  follow  the  movements  of  the  nut  exactly  as 
if  directly  commanded  by  the  screw,  u  u  are  two  pul- 
leys, across  which  passes  the  uncut  part  of  the  screw  z. 
These  pulleys  are  commanded  by  the  other  pulleys  v  v, 
the  one  by  a  straight  strap,  the  other  by  a  crossed  one, 
and  are  turned  in  an  opposite  direction  to  each  other. 

X.  Toothed  shaft,  partaking  of  the  rotatory  motion  of 
the  main  shaf1>,  which,  being  traversed  by  a  pin,  but 
being  movable  to  the  right  or  left  at  pleasure,  and  fitting 
in  the  claws  of  the  pulleys  7i  n,  renders  their  movement 
uniform  with  that  of  the  shaft.  At  the  middle  of 
this  shaft  there  is  a  large  groove,  which  receives  two 
small  iron  stays,  fixed  to  the  interior  of  the  oval  which 
the  lever  y  forms  at  its  junction  with  the  shaft.  This 
lever  is  surmounted  by  a  ball  iv,  and  is  mounted  upon 
an  iron  pivot,  which  is  fixed  upon  the  cross-piece  a',  fas- 
tened at  its  extremities  to  the  supports  n  n. 

y.  Round  iron  rod  having  a  square  part  at  the  end 
which  slides  in  one  of  its  supports,  and  is,  by  this  means, 
prevented  from  being  turned.  This  rod  passes  across  a 
tail-piece,  attached  to  the  nut  t,  and  carries  two  rings,  c'  c', 
fastened  at  a  convenient  part  by  a  compressing  screw. 
The  rod  also  has  upon  it  two  little  projections,  d'  d'. 


226 


BEATING  AND  ROLLING. 


which  engage  the  lever  and  give  it  an  alternate  motion 
to  the  right  or  left,  when  the  tail  of  the  nut  encounters 
alternately  the  rings  d  d , 

e'.  Cast,  marble,  or  wooden  table,  surmounted  by  a 
copper  plate.  The  table,  as  the  plan  shows,  may  be 
either  plane  or  concave,  without  any  injury  to  the  suc- 
cess of  the  process  following."^ 

This  machine  is  intended  to  produce  the  most  com- 
plete contraction  of  the  pores  of  leather  that  can  be 
attained,  by  means  of  two  different  movements  com- 
bined in  one,  and  by  a  pressure  of  from  18  to  20 
thousand  weight  upon  a  surface  of  some  fractions  of  an 
inch,  this  pressure  being  transmitted  through  the  whole 
thickness  of  the  skins  without  injuring  or  abrading  their 
surfaces,  and  compressing  those  of  different  thickness 
with  entire  uniformity. 

The  hides  are  placed  upon  the  table  e;  the  stamper  Z, 
to  which  a  round,  oval,  curved,  or  straight  form  can  be 
given  at  pleasure,  directed  by  the  whole  weight  of  the 
lever  and  the  additional  one  of  the  lever  passes 
over  the  leather  and  receives  the  oscillating  motion  given 
to  the  lever  by  the  cranks  h,  h.  It  also  receives  an- 
other motion  which  makes  it  pass  progressively  across  the 
breadth  of  the  table,  first  in  one  direction  and  after- 
wards in  the  other,  and  which  is  caused  by  the  screw 
which  receives  an  alternate  rotatory  motion  to  the  right 
and  to  the  left,  by  means  of  the  toothed  shaft  which 
catches  in  the  pulleys  to  the  right  and  to  the  left,  being 

*  It  will  be  observed  that  an  occasional  discrepancy  between  tlie  let- 
tering of  tbe  cuts  and  the  references  to  them  in  the  descriptions  occurs 
in  this  and  a  few  other  instances  throughout  the  work.  The  errors  are 
to  be  met  with  in  the  original  French  treatise  much  more  frequently  than 
in  the  present  edition;  and  those  which  have  not  been  altered  from  the 
originals  by  the  engraver,  will  be  detected  at  once  by  any  machinist. 


BEATING  AND  ROLLING. 


227 


governed  by  the  lever  with  the  ball  on  top,  which  is 
drawn  away  from  its  centre  of  gravity  by  the  projections 
cVy  cV,  of  the  rod  and  falls  back  upon  the  opposite 
side. 

The  table  being  higher  on  one  side  than  on  the  other, 
and  the  course  of  the  lever  passing  the  curved  part 
where  it  is  least  elevated,  the  stamper  leaves  the  surface 
of  the  leather  at  short  intervals,  which  are  determined 
by  each  revolution  of  the  wheels  /, /,  and  tbe  pressure 
being  thus  taken  off,  the  leather  can  be  moved  by  the 
workman  and  replaced  in  another  position,  so  that  the 
force  can  be  directed  successively  upon  the  whole  sur- 
face. 

The  results  of  this  operation  are  an  immense  economy 
of  time,  labor,  and  trouble,  the  greatest  possible  amount 
of  compression  and  contraction  of  the  substance  of  the 
leather,  the  securing  of  a  perfectly  uniform  and  smooth 
surface,  and  the  accomplishment  by  one  workman  of 
what  can  only  in  common  be  effected  by  ten  or  twelve. 

Flotard  and  Delhufs  Machine, — The  following  is  a  de- 
scription of  a  machine  invented  in  1842,  by  Flotard  and 
Delbut,  taken  from  the  Eeports  of  expired  French  Patents, 
vol.  Ivii.  p.  86 ;  its  object  being  to  replace  hand-beating 
by  more  active  means,  which  will  be  free  from  the  in- 
conveniences attaching  to  other  machines.  To  attain 
this  end,  the  inventors  have  endeavored  chiefly :  — 

1st.  To  bring  to  perfection  the  construction  of  the 
mechanism  moving  the  hammer,  and 

2d.  To  make  the  anvil  elastic,  so  that  injury  to  the 
leather  by  the  hardness  and  roughness  of  the  blows  may 
be  prevented. 

3d.  To  use  a  table  with  a  rolling  surface,  and  with 
rollers  attached  to  the  feet. 


228 


BEATING  AND  KOLLING. 


Figs.  47,  48,  and  49.  a.  Cam,  intended  to  lower  the 
arm  of  the  lever  c,  so  as  to  elevate  the  hammer  e. 


Fig.  47. 


1).  Framework,  or  cast  beam,  supported  on  three  co- 
lumns and  sustaining  the  whole  apparatus. 


Fig.  48.  Fig.  49. 


c.  Lever,  having  one  extremity  furnished  with  a 
wooden  cushion,  and  the  other  rounded  off  to  enable  it 
to  move  freely  in  the  mortice  of  the  hammer. 

d.  Cast  arm,  the  end  of  which  holds  the  helve  of  the 
hammer  and  maintains  it  in  the  vertical  position. 


BEATING  AND  ROLLING. 


229 


e.  Hammer^  having  its  lower  surface  covered  with 
copper. 

/.  Support,  or  anvil,  composed  of  two  principal  parts  : 
the  one  fastened  to  the  ground,  1,  is  furnished  with  a 
grating,  2,  which  receives  the  fuel,  and  is  attached  by 
screws  to  masonry-work;  the  other  part,  4,  is  that  which 
receives  the  impulse  of  the  hammer.  It  is  movable,  and 
mounted  on  twelve  springs,  3 ;  and  its  upper  surface  is, 
like  the  opposing  one  on  the  hammer,  composed  of  cop- 
per. 

g.  Fly-wheel,  connected  with  the  motive  power  by 
means  of  a  band. 

Figs.  50  to  53.   Hammer,  of  cast  or  wrought  iron.  If 


Fig.  50. 


230 


BEATING  AND  ROLLING. 


sufficiently  small,  it  may  be  solids  but  if  large  should  be 
hollow. 

a,  a'.  "Wooden  teeth,  against  which  the  cam  h  catches. 
These  teeth  are  adapted  to  two  mortices  in  the  upper 
part  of  the  hammer,  and  are  retained  in  place  by  a 
wooden  wedge.  By  means  of  the  two  teeth,  the  ham- 
mer can  be  elevated  more  or  less,  either  by  taking  off  the 
lower  one,  a',  or  by  enlarging  or  diminishing  their  size. 

h.  Cam,  acting  upon  the  teeth  a,  to  elevate  the  hammer. 

d.  Cjdinder,  directing  the  hammer  and  keeping  it  ver- 
tical. This  is  furnished  with  two  projections  3,  which 
support  cushions  for  the  shaft  of  the  cam  h.  It  rests 
upon  a  shoulder  cV,  upon  the  plate  h'.  The  lips  i, 
against  which  the  wooden  teeth  slide,  prevent  the  ham- 
mer from  turning. 

Two  lateral  openings,  o,  o,  Eig.  51  (also  seen  in  Fig. 
50),  allow  the  cushions  r,  r,  (Fig.  52)  to  pass,  which 

Fig.  51.  Fig.  52. 


press  the  levers  Z,  I;  worked  by  a  screw,  to  the  right  at 
one  end,  and  to  the  left  at  the  other.  Fig.  51  exhibits 
this  arrangement. 

The  shaft  m.  Fig.  52,  serves  as  a  prolongation  of  the 
screw  n,  Fig.  51,  and  carries  a  pulley  Fig.  50,  upon 
which  passes  a  cord  having  a  weight  at  one  end,  and  a 
stirrup  for  the  foot  at  the  other.    The  cushions  r,  r,  pro- 


BEATING  AND  EOLLING. 


231 


duce  a  friction  which  slackens  the  fall  of  the  hammer, 
and  diminishes  the  force  of  the  blow. 

cV .  Circular  plate,  or  cup,  intended  to  receive  the  oil 
or  grease  dripping  from  the  machinery,  and  which 
might  otherwise  fall  upon  and  soil  the  leather.  Fig.  50. 
Two  vertical  pieces,  supporting  horizontally  a  rabbit,  or 
wooden  spring,  which  is  elevated  or  depressed  by  the 
screw  attached  to  one  end  of  it,  so  that  the  hammer  a,  in 
rising,  touches  it  with  more  or  less  force,  so  as  to  aug- 
ment the  power  of  the  blow.  A  metal  spring  may  be 
used  in  the  place  of  a  wooden  one. 

/.  Figs.  53  and  54.  Table  with  rollers, its  feet  rest 
on  iron  rails. 

Fig.  53. 


r.  Wheels,  adapted  to  the  feet  of  the  table  and  running 
upon  the  rails.    The  skins  to  be  beaten  are  placed  on 


232 


BEATING  AND  ROLLING. 


this  table,  and  upon  its  middle  the  anvil,  upon  which 
the  hammer  descends,  is  supported. 

Fig.  54. 


3_ 


The  anvil  is  chambered  for  the  passage  of  a  current 
of  steam,  for  the  purpose  of  warming  the  copper  face,  y ; 
and  it  rests  upon  springs,  which  are  intended  to  render 
the  shock  of  the  hammer  less  severe,  and  to  diminish 
the  jarring. 

As  the  system  of  vertical  hammers  has  long  been  in 
common  use,  the  invention  of  Flotard  and  Delbut  con- 
sists really,  only  in  the  use  of 

1.  The  spring,  for  increasing  the  force  of  the  blow. 

2.  The  check,  for  diminishing  it. 

3.  The  cups,  for  receiving  the  oil  drippings. 

4.  The  movable  table,  with  rollers. 

5.  The  arrangement  of  springs,  under  the  face  of  the 
anvil,  and 

7.  In  the  passage  of  vapor. 

M.  Berendorfs  Machine  for  Pressing  Hides. — The  fol- 
lowing report  upon  and  description  of  this  machine  is 
from  the  Bulletin  of  the  Society  for  Encouragement  of 
Arts,  &c.,  of  the  year  1845,  p.  68. 

The  necessity  of  hammering  by  hand  skins  intended  for 
sole  leather,  formerly  a  very  essential  though  fatiguing 
means  of  compressing  them,  has  now  been  almost  entire- 
ly prevented  by  methods  which  much  more  effectually 
answer  the  same  purposes.  Among  these  means  that  of 
M.  Berendorf,  which  substitutes  for  hammering  a  rapidly 


BEATING  AND  ROLLING. 


233 


applied  compression,  somewhat  analogous  to  it  in  opera- 
tion, has  been  very  successful. 

The  peculiarity  of  the  mode  employed  by  him  in  the 
use  of  the  machine  invented  in  1844,  consists  not  so 
much  in  this  substitution  of  rapid  compression  for  ham- 
mering, as  in  the  peculiar  arrangement  of  the  support  for 
the  leather,  which,  by  its  elasticity,  makes  it  possible  to 
confine  the  amount  of  pressure  to  any  desired  limits. 
The  support  is  an  anvil,  resting  upon  a  spring  composed 
of  hard  wood,  the  amount  of  resistance  of  which  can 
be  modified  at  pleasure  by  the  workman,  w^ho,  holding 
the  hide  by  one  hand,  turns  with  the  other  a  screw  which 
exactly  regulates  the  pressure  to  which  any  particular 
part  of  the  leather  may  be  exposed. 

"  The  machine  of  Berendorf  is  powerful,  and  simple 
in  all  its  parts.  A  beam  acts  upon  a  lever,  the  fixed 
point  of  which  is  attached  to  a  cast-iron  support,  which 
forms  the  top  of  a  frame  large  enough  to  receive  a  great 
number  of  hides,  and  having  in  its  middle  an  opening 
through  which  the  piston  which  produces  the  com- 
pression by  means  of  a  lever  about  to  be  described,  slides. 

"  The  compressing  surfaces  in  contact  with  the  hides, 
are  made  of  brass,  are  smooth,  convex,  circular,  and 
have  a  diameter  of  from  SiVth  to  Sjoth  inches.  The 
skins  exposed  to  their  action  are  beautifully  smoothed 
and  perfectly  compressed  by  it. 

^^The  advantages  of  this  process  in  improving  the 
quality  and  appearance  of  leather,  and  its  superior  cheap- 
ness, have  induced  the  council  to  bestow  upon  M.  Beren- 
dorf a  silver  medal,  and  to  insert  in  their  Bulletin  this 
report,  accompanied  by  a  description  and  plate." 

This  machine  is  composed,  1st,  of  a  movable  vertical 
hammer,  which  exerts  pressure  upon  the  hides.    2d.  Of 
16 


234 


BEATING  AND  ROLLING. 


a  fixed  anvil,  upon  which  they  are  placed.    3d.  Of  a 
lever  which  gives  the  impulse  to  the  hammer. 
Fig.  55  exhibits  a  front  view  of  the  machine. 


Fig.  55. 


Fig.  56.  A  plan. 

rig.  66. 


Fig.  57.  Vertical  and  cross  section,  made  upon  the 
line  A,  B,  in  the  first  figure. 


BEATING  AND  ROLLING. 


235 


The  same  letters  apply  to  all  the  figures. 

1.  The  wrought-iron  hammer,  A,  is  furnished,  at  its  in- 


cal  shank  or  helve  passes  through  a  vertical  socket  in 
the  large  and  strong  cast-iron  beam  B.  This  latter, 
which  is  represented  in  cross  section  by  Fig.  58  (upon 
the  line  C  B,  Fig.  55),  is  strengthened  by  mouldings, 
and  rests,  by  its  extremities,  upon  two  cast  upright 
columns  C  C,  with  which  it  is  firmly  connected.  The 
space  between  these  uprights,  amounting  to  but  78 
inches,  only  admits  half  hides,  although  M.  Berendorf 


236 


BEATING  AND  ROLLING. 


has  also  adopted  another  arrangement,  represented  in 
Fig.  59,  which  admits  of  acting  upon  whole  ones.  About 
the  middle  of  the  upper  part  of  the  beam  and  near 
the  socket,  is  a  projection  D,  which  supports  the  end  of 
the  lever  that  transmits  its  action  to  the  hammer. 

2.  The  anvil  which  receives  the  leather  to  be  com- 
pressed, is  composed  of  an  iron  cylinder  having  a 
brass  face  a',  like  that  of  the  hammer,  and  between  these 
two  the  leather  is  pressed  when  the  latter  descends. 

The  cylinder  passes  freely  through  the  socket  of  the 
large  cross-piece  and  rests  upon  an  elastic  support, 
which  allows  it  to  descend  a  little  under  heavy  pressure, 
and  to  rise  again  rapidly.  This  support  consists  of  a 
thick  wooden  plank  20  inches  square,  fixed  at  its  ends 
to  the  lateral  projections  c,  which  descend  to  the  foot  of 
the  columns  with  which  they  are  connected.  This  piece 
of  wood-work  is  so  large  that  it  often  has  to  be  made  of 
two  pieces  bound  together  by  screws  with  nuts  d.  The 
cylinder  does  not  rest  directly  upon  this  wood,  but  upon 
a  steeled  gudgeon,  or  pin,  Fig.  60,  e  /.  The  gudgeon  or 
pin  is  threaded  for  part  of  its  length,  and  traverses  a 
copper  nut  </,  sunk  in  a  cast-iron  rim  A,  which  is  let  into 
the  centre  of  the  wooden  support.  By  turning  this  pin 
to  the  right  or  left,  the  cylinder  and  the  anvil-face  a'  are 
made  to  rise  or  fall  along  with  it.  To  effect  this  move- 
ment, the  workman  grasps  a  little  fly  H,  the  axle  of 
which  has  an  endless  screw  which  works  a  toothed-wheel 
/,  mounted  upon  the  gudgeon.  The  fly  is  turned  more 
or  less,  as  the  thicker  or  thinner  parts  of  the  leather  are 
being  exposed  to  pressure. 

The  leather  placed  between  the  anvil  and  hammer  is 
thus  pressed  to  any  desired  extent,  and,  the  wood  below 
being  elastic,  bends  or  gives  to  some  extent,  and  again 
rebounds  to  its  original  position. 


BEATING  AND  ROLLING. 


237 


The  cast  cross-piece  F  which  guides  the  anvil,  rests  at 
its  two  ends  upon  the  projections  ii  of  the  columns  G  (7, 
and  upon  each  side  of  it  is  placed  a  table  upon  which 
the  workman  moves  the  hide  in  every  direction^  so  that 
it  may  be  touched  at  all  points  successively. 

3.  The  lever  which  acts  on  the  hammer.  The  head 
of  the  hammer  A  incloses  a  steel  block,  upon  which  a 
prop  j  pivots,  which  is  of  ovoid  form  and  well-tempered 
steel  (Fig.  57) ;  and  upon  this  prop  the  large  lever 
moving  upon  the  axis  h,  Fig.  61,  is  supported.  When 
it  descends,  it  rests  upon  the  prop  y,  which  oscillates  a 
little  upon  its  centre,  and  forces  down  the  hammer  in  a 
vertical  direction,  and,  in  order  that  it  may  rise  again 
with  it,  they  are  connected  together  by  two  iron  bars, 
terminated  by  arms,  which  are  attached  on  one  side  by 
the  bolt  rriy  which  passes  through  the  lever,  and  on  the 
other  by  a  similar  bolt  n,  which  goes  through  the  head 
of  the  hammer  (Fig.  57).  The  play  given  to  these 
arms  is  regulated  by  small  compressing  screws  above 
them. 

The  steel  axis  upon  which  the  lever  moves,  rests 
upon  the  upper  part  of  the  projection  D.  A  steel  ring, 
traversed  by  the  axis  is  adjusted  upon  the  centre  of 
the  lever-head,  and  can  be  easily  replaced  when  worn 
out.  In  order  to  retain  this  axle  in  place,  it  is  covered 
on  each  side  of  the  lever  by  two  strong  stays,  the 
branches  of  which  extend  to  the  top  of  the  beam,  as  well 
as  to  the  projection  D,  and  are.  kept  in  place  by  strong 
nuts. 

M.  Berendorf  moves  his  machinery  by  a  small  oscillat- 
ing cylinder  engine,  the  power  being  transmitted  to  the 
lever  K  by  the  two  beams  L  X,  joined  together  by  the 
double  crank  M.    The  vapor  enters  the  conical  box 
from  the  boiler  through  the  pipe  5,  raises  the  piston,  and 


238 


BEATING  AND  ROLLING. 


escapes  by  the  pipe  t.    The  fly  R  turns  the  small  crank 

and  works  the  feeding-pump  which  is  plunged  in 
the  reservoir  T,  The  water  is  returned  into  the  boiler 
by  the  tube  a'',  when  the  cock  h'  is  open,  and  a  ball-cock 
keeps  up  the  communication  between  a  reservoir  above 
and  the  one  below. 

This  machine  works  ordinarily  at  the  rate  of  140  revo- 
lutions in  the  minute,  during  which  time  more  than  a 
square  yard  of  surface  is  compressed  by  it.  In  M.  Beren- 
dorf's  establishment,  where  a  number  of  machines  are 
constantly  working,  from  70  to  80  half  skins  are  pressed 
by  each  apparatus  in  twelve  hours. 

Berenger  and  Co.  have  three  mill-hammers  at  work, 
at  the  rate  of  100  blows  a  minute,  each  one  turning  out 
from  35  to  40  whole  skins  in  a  day. 

M.  Berendorf  has  taken  out  a  patent  of  fifteen  years 
duration,  dating  the  7th  of  October,  1842,  and,  still  later, 
two  additional  ones  of  improvements  upon  this  interest- 
ing machine,  which  is  now  completely  established  in 
favor. 

Coxs  Machine. — A  more  modern  method  of  rendering 
leather  smooth  and  compact,  is  by  passing  it  between 
rollers.  This  mechanical  arrangement,  being  free  from 
tremulous  motions,  and  easily  adjusted  to  any  desired 
rapidity  of  action,  produces  a  uniform  and  powerful 
compression  throughout  the  side  of  leather,  without  any 
liability  of  damaging  it,  as  is  the  case  in  machine  heating. 

Cox  has  invented  a  rolling-mill  in  which  the  roller  is 
fixed  at  the  end  of  a  lever,  which,  being  suspended, 
oscillates  like  the  balance  of  a  pendulum. 

This  roller,  made  of  copper  or  brass,  5  inches  in 
diameter  and  9  inches  in  length,  is  suspended  by  its 
axes  in  the  chaped  end  of  an  iron  lever,  6  inches  in 
diameter  and  11  feet  10  inches  long.    The  upper  end  of 


BEATING  AND  ROLLING. 


this  lever,  also  terminating  in  a  chape,  is  movable  upon 
pivots  attached  to  a  beam  or  block  15  feet  long  and  2 
feet  wide.  This  beam  is  free  at  its  anterior  extremity, 
and  is  so  jointed  at  the  other  as  to  enable  it  to  move 
upwards  and  downwards,  and  it  rests  on  each  side  upon 
two  supports  placed  below  it.  The  weight  is  in  a  box 
resting  upon  the  body  of  the  lever,  which  is  moved  by 
the  aid  of  a  crank  attached  to  it  at  a  distance  of  rather 
less  than  two  feet  above  the  roller.  The  lever  should 
move  through  a  space  of  3  feet  8  inches,  but  this  can  be 
increased  or  diminished.  The  copper  or  brass  support 
is  hollowed  out,  so  that  the  roller  can  pass  along  its 
whole  extent,  and  reach  all  parts  of  the  leather.  As 
soon  as  the  hide  is  placed  upon  this  support,  the  block 
or  beam  is  made  to  rise,  and  the  whole  weight  bears 
directly  upon  the  leather.  At  the  end  of  its  course, 
where  the  support  is  flat,  the  roller  is  raised  up  by  the 
beam,  the  weight  is  borne  down  again  upon  the  leather 
when  it  reaches  the  middle,  and  is  again  elevated  by  the 
supports  placed  under  the  beam. 


Fig.  62.  Fig.  63. 


240 


BEATING  AND  ROLLING. 


Fig.  62  is  a  front  view,  and  Fig.  63  a  side  view,  of  this 
machine.    F,  beam,  movable  at  its  hind  end  by  a  hinge 
C  fixed  in  the  wall,  (Fig.  64),  and  maintained  in  a  hori- 
zontal position  at  the  other  end  by  the  sup- 
ports  BB.    P,  lever  joined  to  the  beam  i^by 
the  pivots  S  S,  and  terminated  by  a  fork  M, 
which  holds  the  roller      running  over  the 
curve  A.    This  curve  has,  at  either  end,  a 
plane  surface  B,  where  the  roller  leaves  it  and  is  raised 
up  by  the  pivots  S.    D  is  the  horizontal  shaft  connected 
with  a  crank  which  moves  the  lever  P,  and  (7  is  a  box 
containing  a  weight  heavy  enough  to  cause  the  neces- 
sary pressure  at  the  moment  when  the  roller  reaches  the 
plane  end  of  the  support. 

Wiltses  Rolling  Table. — This  machine,  somewhat  simi- 
lar in  construction  to  the  preceding,  is  shown  by  the 
accompanying  drawing,  Fig.  65,  made  to  a  scale  of  the 


Fig.  65. 


eighth  of  an  inch  to  a  foot.  The  machine  consists  of  a 
spring  pole,  a  lever  h,  to  which  the  head  of  the  vibra- 
tor d  is  attached,  and  which  is  rendered  compound  by  a 


BEATING  AND  ROLLING. 


241 


connection  with  a  second  lever  c.  This  combination 
acts  through  the  vibrator  d  upon  the  roller  and  is 
propelled  by  the  foot  working  the  treadle  e  e.  The  bed 
h  is  of  lignum vitse  wood,  and  the  table  ^,  upon  which 
the  leather  is  spread  while  being  gradually  drawn  under 
the  roller,  is  8  feet  wide  and  16  long.  The  bed  is  the 
part  upon  which  the  leather  is  rolled,  and  is  firmly  sup- 
ported by  a  heavy  log  J,  which,  in  its  turn,  rests  securely 
upon  the  supports  o  o  o  o  and  the  sill  n  of  the  building. 
The  connection  /  with  the  balance-wheel  h  forms  a  crank 
by  which  a  vibrating  motion  is  communicated  to  d.  The 
pulley  m  on  the  same  shaft  is  the  driving  medium,  and 
the  roller  should  move  at  the  rate  of  130  revolutions  a 
minute. 

Fig.  66  is  a  view  of  the  rollers  A  A,  one  of  which  is 


Fig.  66. 


.A 


242 


BEATING  AND  ROLLING. 


represented  as  it  is  retained  in  working  position  by  the 
straps,  B  B,  and  the  other  detached.  A  side  view  of 
the  strap  is  also  given  in  a  separate  figure  B,  The 
wrench  O  is  used  for  turning  the  nuts  K  The  lips  F  F 
are  oil-holes  for  lubricating  the  journals  of  the  roller. 

The  roller  is  made  of  a  composition  of  copper  and  tin, 
with  a  steel  shaft  penetrating  through  it. 

These  mills  and  appliances  are  made  in  a  creditable 
style  of  art  by  Wiltse  and  Co.,  Catskill,  New  York. 


CHAPTER  XY. 


IMPROVED  PROCESSES. 

Having  treated,  in  detail,  of  the  practices  of  the  art, 
as  well  as  its  chemical  theory,  the  reader  may  now  be 
considered  sufficiently  conversant  with  the  subject  to 
detect  and  apply  the  good  points  of  the  so-called  ^'im- 
proved" processes  which  we  are  about  to  present. 

Seguin,  the  friend  and  colleague  of  the  lamented  La- 
voisier, devoted  himself  particularly  to  the  improve- 
ment of  the  tanner's  art,  by  chemical  exjoeriment  and 
inquiry;  and  was  the  first  to  make  known  the  distinction 
between  gallic  acid  and  tannin,  and  the  property  which 
the  latter  possesses  of  combining  with  various  animal 
substances,  especially  gelatine,  forming  with  it  the  un- 
alterable basis  of  leather.  The  determination  of  this 
important  fact  revealed  the  key  to  the  whole  process, 
and  was  the  foundation  of  his  own  researches  and  labors, 
as  well  as  of  those  of  all  who  have  since  followed  in  his 
footsteps. 

seguin's  process. 

Seguin's  mode  of  proceeding  was  as  follows:  His 
preliminary  processes  were  the  same  as  those  of  others, 
excepting,  according  to  Dessables,  that  he  directed  the 
skins,  after  soaking  and  fleshing,  to  be  rinsed  in  run- 
ning water,  so  that  all  parts  of  them  should  be  exposed 
to  contact  with  it.    He  first  deprived  them  of  hair 


244  IMPROYED  PROCESSES. 

by  means  of  lime,  and  then  deposited  them  in  tan- 
juice,  with  which  was  mixed  one-five  hundredth,  and 
sometimes  one-thousandth  part  of  sulphuric  acid.  For 
raising  the  hides,  he  first  used  a  vat  lined  with  a  cement 
containing  a  little  lime,  and  filled  with  water  acidulated 
with  one-fifteen  hundredth  part  of  sulphuric  acid;  but 
this  did  not  answer  the  intended  purpose,  as  the  acid, 
instead  of  mixing  with  the  water,  combined  with  the 
lime.  He  therefore  substituted  wooden  tubs  for  vats, 
filled  them  with  w^ater  charged  with  one  fifteen  hundredth 
of  concentrated  sulphuric  acid,  which  was  gradually  in- 
creased to  one-thousandth  part,  and  by  this  arrangement 
succeeded,  according  to  the  report  made  by  him  to  the 
committee  of  public  welfare,  in  raising  hides  in  forty- 
eight  hours.  He  asserted,  however,  that  this  operation 
of  raising  was  not  essential,  and  that  he  procured  excel- 
lent leather  from  skins  which  had  not  been  submitted  to 
the  treatment. 

He  did  not  stratify  the  skins  in  tan-vats,  but  placed 
them  in  vats  filled  with  ooze."  For  procuring  this  so- 
lution, a  number  of  tubs  were  placed  in  a  row,  and  filled 
with  ground  tan.  A  certain  amount  of  water  was  then 
emptied  into  each  tub,  and  filtering  through  the  tan, 
dissolved  out  its  soluble  particles,  and  descending,  ran 
into  receiving  vessels  beneath.  The  liquid  from  the 
first  vat  was  then  thrown  into  the  second  one,  and  so  on 
through  the  range,  until  it  became  saturated.  As  a  con- 
siderable quantity  of  available  material  still  remained 
in  the  tubs,  they  were  affused  with  fresh  water,  which  by 
a  process  of  displacement,  continued  extracting  the  solu- 
ble matters  until  the  tan  was  entirely  exhausted. 

Seguin  placed  the  skins,  after  being  taken  from  the 
acid  bath,  in  a  very  weak  infusion  of.  tan,  and  there 
allowed  them  to  remain  only  an  hour  or  two  for  the  pur- 


IMPROVED  PROCESSES. 


245 


pose  of  giving  color  to  the  hair  sides.  They  were  then 
taken  out  and  immersed  in  a  stronger  solution,  and 
again  and  again  deposited  in  infusions,  increasing  each 
time  in  strength  until  the  tanning  was  entirely  com- 
pleted. 

Oah  Tanning. — A  patent  was  taken  out  in  London,  in 
the  year  1804,  for  a  tanning  process,  which  is  founded 
upon  the  principles  estabUshed  by  Seguin.  The  oak 
bark  is  boiled  for  four  hours  in  a  copper  boiler,  and  when 
the  tan  is  perfectly  exhausted,  the  decoction  is  allowed 
to  flow  off  through  tubes  into  the  vats,  where  it  is  cooled. 
The  skins  are  deposited  in  this  after  being  soaked  and 
pressed,  and  if  they  exhaust  the  liquor  before  the  close 
of  the  process,  a  fresh  decoction  is  substituted.  If  it  is 
desired  to  have  the  hair  side  color  whiter  than  ordinary, 
tan  is  mixed  with  the  liquor.  By  this  means  a  great 
amount  of  tannin  is  concentrated  in  a  small  quantity  of 
material,  and  much  less  labor  is  required  than  in  com- 
mon; ten  or  twelve  days  producing  as  great  an  effect 
as  eight  or  nine  months  of  exposure  by  the  old  method. 
It  is  believed,  however,  that  the  skins  are  not  thoroughly 
tanned  by  it,  and  that  the  leather  is  of  deficient  quality. 
The  great  quantity  of  tannin  presented  to  the  skins,  tans 
their  surfaces  rapidly,  and  prevents  the  entrance  of  the 
liquid  into  the  interior. 

The  patentees  use,  besides  the  ground  oak-bark,  the 
chips  and  sawdust  of  the  wood,  and  ordinary  furze,  and 
recommend  the  employment  of  young  shoots,  the  roots, 
and  superfluous  branches  of  the  oak,  by  the  use  of  which 
they  say  that  they  procure  a  stronger  decoction  than  that 
from  the  bark  of  the  trunk,  which  contains  a  thick  mat- 
ter incapable  of  being  separated. 

In  1819,  new  improvements  were  introduced.  The 
trunk,  roots,  branches,  and  leaves  of  oak  being  asserted 


246 


IMPROVED  PROCESSES. 


to  contain  enough  tannin  to  warrant  their  employment 
in  tanning,  were  reduced  to  the  state  of  chips  or  coarse 
powder,  boiled  in  water,  and  used  in  the  following  man- 
ner : — 

For  the  tanning  of  calf  or  other  light  skins,  one  hun- 
dred pounds  of  the  middle  parts  or  branches  of  the  oak 
in  chips,  is  boiled  in  a  copper  boiler,  with  fiftj-two  gallons 
of  water  until  the  latter  is  reduced  to  thirty-nine  gallons. 
This  liquid  is  decanted,  and  upon  the  residue,  is  poured 
a  second  quantity  of  thirty-nine  gallons  of  water,  which 
is  boiled  away  to  twenty-one  gallons.  This  decoction  is 
set  aside  and  serves  for  the  first  bath  of  the  calf-skins 
after  they  have  been  cleaned  upon  the  horse,  while  the 
first  liquor  is  used  for  the  second  bath. 

To  tan  common  skins,  a  hundred  pounds  of  the  middle 
parts  or  branches  of  oak  in  chips,  seventy-five  pounds  of 
fresh  coarse  tan,  and  twenty-seven  and  a  half  pounds  of 
the  root,  are  boiled  in  sixty-six  gallons  of  water,  until 
the  latter  is  reduced  to  two-thirds.  The  decoction  is 
then  decanted  off  from  the  partially  exhausted  matter, 
and  fifty-two  gallons  more  of  water  are  poured  upon  it 
and  boiled  until  reduced  to  one-half.  This  liquid  is  used 
as  the  first  bath  for  the  skins,  and  the  one  previously 
obtained  as  the  second ;  and  when  they  have  been  ex- 
posed long  enough  to  both,  enough  fresh  bark  or  tan- 
liquor  to  complete  the  tanning,  is  added.  This  method 
seems  to  be  very  incomplete  throughout,  and  the  in- 
ventors have  failed  to  make  known  the  proportions  of 
tanning  material  to  the  number  of  skins,  and  the  length 
of  time  required  for  the  completion  of  the  processes. 

In  these  tannings,  the  skins  were  not  thrown  promis- 
cuously into  the  vats,  but  were  suspended  vertically  at 
intervals  of  about  an  inch  from  each  other,  so  as  to  pre- 
vent the  surfaces  from  touching;  and  to  facilitate  this 


IMPROVED  PROCESSES. 


247 


mode  of  suspension,  they  directed  the  heads  of  the  skins 
to  be  cut  off,  and  bands  on  each  side  having  attached 
to  them  the  legsand  parts  of  the  beUies,  to  be  removed. 
The  bodies  of  the  skins  were  then  to  be  divided  into  pieces 
proportioned  to  the  depth  of  the  vats,  which  pieces  were 
to  be  suspended  in  them,  while  the  other  parts,  being  of 
less  value,  were  thrown  together  into  the  bottom. 

In  tanning  skins  for  uppers,  after  washing  and  fleshing 
them,  Seguin  directs  that  they  be  freed  from  hair  by 
soaking  in  clear  lime-water,  and  then,  without  being 
raised,  tanned  in  weak  solutions  of  bark  made  into  a 
kind  of  ooze.  The  strength  of  these  solutions  was  to  be 
gradually  increased,  but  not  to  the  point  of  complete 
saturation,  as  in  the  case  of  strong  hides.  He  succeeded 
in  this  way  in  tanning  leather  for  uppers  in  three  or  four 
days. 

The  methods  of  tanning  proposed  by  Seguin  are  rapid 
in  the  extreme,  but  they  have  not  been  generally  adopted, 
since  the  leather  made  by  them  is  inferior  to  that  by  the 
old  process,  and  is  less  merchantable.  It  is  possible, 
that  if  public  business  had  not  drawn  away  the  attention 
of  Seguin  from  his  investigations,  he  might  have  succeeded 
in  effecting  a  complete  revolution  in  the  art  of  tanning. 
As  it  is,  he  has  had  numerous  followers,  many  of  whom, 
in  England  and  elsewhere,  have  patented  and  used  varia- 
tions of  his  process;  but  the  essential  objection  to  this 
mode  of  operating  still  attaches  to  all  of  them,  namely, 
that  the  combination  of  tannin  with  the  gelatine  and 
fibrine  upon  the  surface  of  the  skins,  takes  place  so 
rapidly,  that  the  superficial  layer  of  leather  thus  formed 
prevents  the  passage  of  the  liquor  into  the  interior  of 
the  hide,  and  consequently  its  perfect  tanning. 

Desmond  has  proposed  a  modification  of  Seguin's  pro- 
cess, which  consists  in  soaking  the  skins  until  the  hair 


248 


IMPROVED  PROCESSES. 


gives,  in  a  liquor  saturated  with  tanning  principle,  and 
acidulated  with  a  thousandth  part,  by  measure,  of  oil  of 
vitriol.  When  it  is  desired  to  raise  the  skins  to  any  ex- 
tent, they  are  immersed  from  ten  to  twelve  hours  in  water 
containing  a  five  hundredth  volume  of  sulphuric  acid, 
then  rinsed  in  fresh  water,  and  worked  on  the  beam. 
Finally,  they  are  soaked  in  a  weak  ooze,  and  after  some 
hours,  transferred  to  a  stronger  infusion,  and  left  therein 
for  several  days.  This  last  liquor  must  be  replaced  by 
fresh  infusion  as  fast  as  it  loses  its  tanning  power. 

getliffe's  process. 

This  method,  patented  in  1812,  consists  in  having  a 
building  with  two  stories,  in  the  lower  of  which  are  the 
vats  and  boilers,  and  in  the  upper,  the  leech-tubs  for 
preparing  the  tan-liquor.  The  loft  may  be  arranged  as 
a  drying  apartment. 

Boiling  water  is  raised  by  means  of  a  pump,  from  a  boiler 
below  into  the  reservoir,  and  a  pipe  connecting  the  two 
returns  the  extract  of  tan  to  the  boiler,  from  which  it  is 
distributed  by  means  of  pipes  with  stop-cocks,  into  the 
different  vats.  These  vats  are  supported  upon  frame- 
work, and  passing  around  them  are  pipes,  by  means  of 
which  their  contents  are  kept  at  a  uniformly  elevated 
temperature.  Each  vat  also  has  a  stop-cock  in  its  lower 
part,  which  permits  its  contents  to  be  emptied,  when  it  is 
desired. 

The  rough  skins  are  thrown  into  the  vats ;  and  are  said 
to  be  tanned  in  them  in  one  quarter  of  the  usual  time. 

nossiter's  process. 

This  new  method  was  patented  in  England  in  1844, 
and  consists  in  depositing  the  skins  in  pits  so  that  they 


IMPROVED  PROCESSES. 


249 


sliall  not  be  subjected  to  the  pressure  of  those  placed 
above  them,  and  in  pressing  out  the  exhausted  infusion 
contained  in  them,  before  immersing  them  again  in 
fresh  ooze. 

1.  The  skins  being  superposed,  in  the  old  method  of 
tanning  in  vats,  those  which  are  below  are  so  compressed 
that  the  tan-liquor  penetrates  their  structure  with  diffi- 
culty. To  avoid  this  objection,  the  inventor  proposes  to 
deposit  the  skins  in  square  vats,  and  to  separate  them  by 
the  interposition  of  rectangular  frames  with  ledges.  By 
this  means  the  skins  are  perfectly  free  from  contact  with 
each  other  while  in  the  tan-liquor. 

Fig.  67  represents  a  horizontal  section  of  the  vat,  and 
a  frame  with  a  skin  stretched  over  it. 


Fig.  67. 


Fig.  68  is  a  vertical  section,  showing  the  frames  in 
stack,  and  the  skins  between  them. 


Fig.  68. 


17 


250  '      IMPROVED  PROCESSES. 

Fig.  69  shows  the  plan  of  the  bottom  of  the  vat. 


Fig.  69. 


Fig.  70,  plan  of  the  frame. 


Fig.  70. 


a,  a.  Vat,  of  the  ordinary  form ;  wooden  frame, 
with  crosspieces;  ledges,  for  maintaining  the  pieces  in 
position. 

This  method  of  tanning  is  much  more  expeditious 
than  the  old  way ;  for  although  fewer  skins  can  be  tanned 
by  it  at  one  time,  it  admits  the  w^orking  of  a  greater 
number  in  a  given  time,  and  in  the  same  vat. 

The  vat  is  first  filled  with  the  skins  and  frames,  and 
the  tan-liquor  is  then  introduced.  When  this  latter  is 
exhausted  or  weakened,  it  is  pumped  out  and  replaced 
by  fresh  ooze. 

The  skins  are  deprived  of  exhausted  liquor,  in  many 
establishments,  by  pressure  between  rollers ;  but  as  this 
method  does  not  fully  effect  the  object,  Nossiter  subjects 
them  to  the  action  of  a  screw-press,  which  is  seen  in 
vertical  section  in  Fig.  71,  and  in  the  plan,  Fig.  72. 


IMPROVED  PROCESSES.  251 

This  press  consists  of  a  strong  rectangular  support 
from  the  four  corners  of  which  arches  spring,  which 

Fig.  71. 


meet  in  the  centre  in  a  square  nut  li^  in  which  the  strong 
screw  i  turns.    The  skins  are  placed  above  each  other 

Fig.  72. 


on  the  table  of  the  frame^  and  are  pressed  by  the  plate 
Z-,  at  the  lower  end  of  the  screw,  which  is  turned  by  the 
lever  I.  The  skins  are  subjected  to  this  pressure  until 
all  their  fluid  contents  are  expelled. 


Fig.  73. 


252 


IMPROVED  PROCESSES. 


In  place  of  the  screw-press,  one  with  an  axle,  seen  in 
Fig.  73  in  vertical  section,  and  in  Fig.  74  in  plan,  may 


Fig.  74. 


1" 

J 

1  I 

a  

I 

f  - 

I 

/I 

i 

be  used.  Around  the  axle  the  cords  n,  are  rolled, 
which  pass  through  pulleys  in  the  supports.  The  cords 
are  passed  at  their  ends  through  screw-rings  on  the  sides 
of  the  under  surface  of  the  plate  By  turning  the 
axle  with  the  lever  the  upper  plate  is  made  to  com- 
press the  skins  which  are  placed  below  it. 

OGEREAU'S  PROCESS. 

Ogereau,  one  of  the  most  eminent  tanners  in  Paris, 
proposes  to  lessen  the  duration  and  labor  of  the  tanning 
process,  by  a  methodical  arrangement  of  materials.  He 
places  alternate  layers  of  tan,  and  of  the  skins  which 
have  been  properly  prepared  by  the  ordinary  method  of 
separating  the  hair  and  of  raising^  in  a  vat  with  a  per- 
forated false  bottom.  This  vat  being  three-quarters  filled, 
is  then  drenched  with  water  for  the  first  operation,  and 
with  weak  tan-liquor  which  has  been  already  used,  for 
the  succeeding  ones.  The  liquid  penetrates  the  mass 
slowly,  and  having  moistened  all  the  contents,  passes 
through  the  false  bottom  into  a  reservoir,  from  which  it 


IMPROYED  PROCESSES. 


253 


is  carried  up  and  again  thrown  upon  the  surface  of  the 
materials  in  the  vat  by  means  of  a  pump. 

The  arrangement  of  Ogereau  consists,  according  to 
Dumas,  of  six  vats,  each  of  which  is  capable  of  contain- 
ing 100  domestic  or  120  imported  hides.  The  liquid 
which  percolates  through  the  contents  into  the  reservoir 
below,  is  daily  distributed  over  the  surface  by  pumping,  a 
constant  circulation  of  fluid  being  kept  up,  which  is  thus 
alternately  receiving  tannin  from  the  bark,  and  render- 
ing it  to  the  skins.  This  operation  is  continued  for  a 
month ;  at  the  end  of  which  time  the  vat  is  emptied,  the 
spent  tan  replaced  by  fresh,  and  the  same  process  is  re- 
commenced. A  third  exposure  to  fresh  tan  and  repeated 
filtrations  are  necessary  before  the  skins  are  properly 
prepared. 

All  the  parts  of  this  process,  including  the  preliminary 
preparation  of  the  skins,  occupy  less  than  four  months, 
and  the  leather  obtained  by  it  is  equal  in  quality  to 
any  procured  by  the  old  methods.  A  hundred  parts  of 
dry  Buenos  Ayres  hides  gives  one  hundred  and  fifty 
parts  of  leather. 


CHAPTEE  XYI. 


YAUQUELIN'S  PROCESS. 

This  process  consists  in  the  use  of  a  machine  by  means 
of  which  hides  are  deprived  of  hair,  and  rendered  soft 
and  suj)ple  without  the  aid  of  chemical  agents,  and  by 
which  they  are  also  fleshed,  and  reduced  to  a  uni- 
form thickness,  thus  saving  much  time  and  labor;  and 
finally  of  a  particular  means  of  tallow^ing  and  dressing 
them. 

The  hides  are  soaked  while  still  raw  for  a  sufficient 
length  of  time,  usually  about  forty-eight  hours,  and  are 
then  subjected  to  the  action  of  the  fulling  machine,  re- 
presented in  Fig.  75,  for  an  hour.  They  are  thus  made 
pliable  and  ready  for  being  w^orked. 

They  are  then  placed  in  another  apparatus,  exhibited 
in  Fig.  76  (a  kind  of  churning-vat),  to  the  joint  action 
of  which,  and  of  the  steam  that  is  let  in  to  keep  up  a 
temperature  of  from  104°  to  113°  (Fahrenheit),  they  x.re 
exposed  for  some  time.  After  the  completion  of  this 
part  of  the  process,  they  are  placed  in  a  suitable  vessel 
and  are  kept  for  twenty-four  hours  under  a  current  of 
tepid  water. 

Great  care  must  be  observed  in  preserving  a  uniform 
temperature  throughout,  and  to  this  end  it  is  necessary 
to  test  the  heat  occasionally  with  a  thermometer  or  the 
hand. 


vauquelin's  process. 


255 


No  other  process  is  required  for  dehairing  when  a  small 
number  of  hides  are  operated  upon;  but  as  economy  of 
time  is  an  important  consideration  when  working  upon 
a  large  scale,  Vauquelin  uses  weak  lime-water,  the  tem- 
perature of  the  bath  being  proportioned  to  the  number 
of  hides.  The  hair  will  then  come  of  with  great  ease, 
and  the  skins  are  carefully  and  thoroughly  fleshed  by 
means  of  a  machine  represented  by  Figs.  77  and  78. 

The  hides,  after  being  fleshed,  are  worked  in  the  full- 
ing machine  for  a  length  of  time,  varying  according  to 
their  nature,  and  are  then  replaced  in  the  vat  (Fig.  76), 
and  impregnated  during  some  hours  with  a  weak  tan- 
liquor.  They  are  then  taken  out,  piled  up  for  two  hours, 
and  again  deposited  in  an  infusion  stronger  than  the  first 
one,  and  during  the  first  three  days  are  handled  three 
times  daily,  and  after  that  time,  once  a  day.  Every 
forty-eight  hours  they  are  filled  and  treated  for  half  an 
hour  in  the  churning-vat,  with  the  same  liquor  in  which 
they  are  left  throughout,  until  thoroughly  saturated. 
The  alternate  action  of  the  filling  stocks  and  churn-vat 
softens  and  opens  the  texture  of  the  hides,  and  renders 
them  more  pliable  and  capable  of  absorbing  the  tan- 
liquor,  thus  promoting  economy  of  time  and  money. 

Another  mode  of  preparing  the  skins  is  to  place  them 
in  the  vat  (Fig.  76),  and  to  introduce  steam  into  it,  so  as 
to  elevate  the  temperature  of  the  liquid  to  from  104"^  to 
113°  F.  The  skins  are  kept  in  a  state  of  constant  agi- 
tation and  movement  from  the  bottom  to  the  circumfe- 
rence of  the  vessel  by  the  arms  c,  and  this  churning  is 
continued  until  they  are  deprived  of  the  greater  portion 
of  their  hair.  They  are  then  deposited  in  another  appa- 
ratus (Figs.  79,  80,  and  81),  which  is  moved  by  suitable 
means.  It  consists  of  a  barrel  or  cylinder,  lined  with  pegs, 
and  revolving  in  a  reservoir  of  water,  the  level  of  which 


256 


vauquelin's  process. 


is  about  half  as  high  as  that  of  the  pegs.  The  skins  are, 
by  this  rotatory  motion  and  friction,  deprived  of  their 
hair,  which  falls  to  the  bottom  and  flows  off  with  the 
water  through  a  metallic  grating.  After  this  process,  the 
skins  may  be  shaved  and  fleshed  as  before  described. 

The  method  of  tallowing  the  leather,  as  prescribed  by 
Vauquelin,  is  as  follows  : — 

After  the  skins  have  been  properly  tanned,  their  whole 
surface  is  daubed  over  with  a  mixture  of  oil  and  tallow, 
and  they  are  placed  in  a  peg-lined  cylinder,  or  drum. 
This  drum  being  made  to  revolve  rapidly,  the  pegs  im- 
pinge upon  the  surfaces  of  the  leather,  and  at  the  end  of 
half  an  hour,  the  grease  will  be  found  to  have  penetrated 
it  so  perfectly  and  uniformly  that  the  surface  will  appear 
quite  dry.    It  is  then  taken  out,  stretched,  and  dried. 

Description  of  the  Figures. — Fig.  75.  This  represents 


the  beating  or  falling  machine.  A,  b.  Cog-wheels,  giving 
motion  to  the  shaft  o,  and  to  cams  upon  it,  which  alter- 
nately raise  and  lower  the  hammers  e,  e,  e,  to  which  the 
bar  D  serves  as  a  guide.  A  movable  trough  for  the  skins 
is  seen  below,  c,  c.  Cocks,  which  allow  the  liquid  mat- 
ters contained  in  this  trough  to  escape.  H,  H.  Openings, 
through  which  the  skins  are  introduced  into  the  trough. 
I.  Rack  and  pinion,  by  means  of  which  the  trough  is 


Fig.  75. 


vauquelin's  process. 


257 


moved  to  and  fro,  so  as  to  bring  all  parts  of  the  skins 
successively  under  the  hammers. 

Fig.  76.  Churning  vat.    This  may  consist  of  an  open 

Fig.  76. 


vessel,  but  a  closed  one  will  enable  the  operator  to  main- 
tain a  more  uniform  temperature.  A.  Yat,  closed  by  its 
lid.  B.  Shaft,  carrying  the  cams  or  arms  c,  c.  d,  d. 
Tubes,  through  which  cold  and  hot  water,  the  tanning 
liquor,  and  steam  are  introduced,  e.  Ladder,  by  which 
the  workman  descends  and  regulates  the  cocks,  f,  f. 
Ground  level.  G,  G.  Water  level  in  the  vat.  h.  Door, 
which  closes  the  opening  in  the  vat.  a.  Toothed  wheel, 
communicating  its  movement  to  the  wheel  5,  and  the 
shaft.  The  arms  of  the  shaft  are  straight,  but  may  be 
made  of  various  shapes. 

Figs.  77  and  78.  These  figures  represent  the  machine 


Fig.  77. 


Fig.  78. 


258 


vauquelin's  process. 


for  fleshing  and  paring  the  hides  after  they  have  been 
properly  soaked  and  softened. 

It  is  composed  of  two  cylinders,  A  and  b,  of  copper,  or 
other  suitable  metal,  mounted  upon  a  framework  c,  c, 
and  forming  a  kind  of  cylindrical  press.  The  upper  one 
can  be  elevated  or  depressed  by  means  of  screws  d,  d,  in 
the  upper  crosspiece  of  the  frame,  which  act  both  upon 
the  fixed  supports  h,  h,  and  upon  the  sides  of  the  frame. 
Upon  this  crosspiece,  a  shaft  with  a  small  fly-wheel  i, 
works  the  endless  screws  f,  f,  which  turn  the  cog-wheels 
E,  E,  by  means  of  which  the  screws  d,  d,  are  turned  in 
either  direction.  These  screws  carry,  just  below  the 
wheel  F,  two  shoulders  or  collars  upon  which  the  bar  k 
is  supported,  and  at  the  extremities  of  this  bar,  two  de- 
scending cushions  L  are  attached,  which  support  the  shaft 
of  the  cylinder  A,  and  which  are  elevated  or  lowered  by 
the  bar,  in  accordance  with  the  movement  of  the  screw 
D.  At  the  two  extremities  of  the  cylinders  are  cog-wheels 
of  different  diameters,  M,  N,  m',  n'.  Those  on  the  shaft 
of  the  lower  cylinder  b,  are  so  attached  to  it,  that  it 
shares  in  their  movement,  while  they  are  movable  upon 
it,  and  can  be  slid  to  the  right  or  left  by  two  forks  Q,  Q, 
fastened  to  the  bar  p'",  which  passes  across  the  frame- 
work. The  wheels  m,  m',  are  geared  with  each  other 
when  the  cylinders  are  a  certain  distance  apart,  and 
those  at  n,  n',  engage  in  turn,  when  the  cylinders  are 
brought  in  contact  with  each  other,  so  that  the  cylinders 
turn  simultaneously  in  either  of  these  positions.  At  the 
extremities  of  the  cylinders,  there  is  a  system  of  pulleys 
which  communicate  the  motion  to  the  machine  by  means 
of  straps. 

Upon  the  interior  and  posterior  faces  of  the  machine, 
two  knives  P,  p',  are  fixed,  which  turn  upon  cushions 
supported  by  the  pieces     2'',  seen  on  the  frame.  The 


VAUQUELIN*S  PROCESS. 


259 


knife  p,  has  a  cutting-blade,  which  is  retained  in  place 
and  adjusted  by  means  of  screws,  but  the  knife  p'  is  dull. 

The  skin,  placed  upon  the  upper  cylinder,  is  drawn  in, 
compressed,  and  stretched  out  in  the  direction  of  its 
length,  between  the  two  rollers.  The  wheels  m,  m',  are 
then  put  in  gear,  and  the  knife  p'  is  made  to  pass  over 
the  skin  by  pressing  it  against  the  upper  roller  by  means 
of  a  movable  piece  with  two  handles.  The  skin  being 
now  pressed  between  the  rollers  and  gradually  advancing 
through  them,  the  cutting  blade  which  is  parallel  to  the 
surface  of  the  cylinder  is  put  in  action,  and,  like  the 
ordinary  fleshing-knife,  it  removes  all  the  projections  from 
the  flesh  side,  and  equalizes  the  thickness  of  the  skin. 

Figs.  79,  80,  and  81.    These  figures  represent  the  re- 


Fig.  79. 


Fig.  80. 


Fig.  81. 


volving  cylinder  or  drum  for  depriving  the  skins  of  hair, 
which  has  already  been  partly  described. 

A.  Exterior  of  the  drum;  B,  B,  shaft  of  cylinder;  c, 
cylinder;  D,  crossbars, forming  the  framework;  e,  f,  sepa- 
rate pieces  of  the  set  of  crossbars;  G,  G,  internal  surface 
of  the  cylinder;  h,  wooden  projections,  fixed  upon  this 
surface ;  i,  metallic  plate,  closing  the  surface  of  the  cylin- 
der ;  L,  door,  closing  the  aperture  ;  M,  M,  tubes,  through 
which  water,  tanning  liquor,  and  steam  are  introduced 
into  the  cylinder ;  o,  ladder,  for  the  workman  who  attends 
to  the  stopcocks,  to  descend;  P,  level  of  liquid  in  the 
cylinder;  Z>,  5,  cog-wheels,  communicating  motion  to  the 
cylinder. 


260 


vauquelin's  process. 


Figs.  82^  83,  and  84.   These  figures  exhibit  different 

Fig.  82.       '  Fig.  83.  Fig.  84. 


i 


means  of  keeping  the  skins  pressed  upon  the  table  when 
they  are  subjected  to  processes  of  paring  by  hand. 

a,  a.  Clamp  or  press  for  maintaining  the  skin  in  place ; 
h,  the  table ;  c,  c,  a  vertical  bar  sliding  in  a  groove ;  d, 
the  lever  which  acts  upon  the  press ;  I,  a  catch  which 
stops  the  lever  d;  f,  weight  at  the  end  of  the  lever;  g, 
another  lever  by  means  of  which  the  press  is  raised,  as 
has  been  before  explained. 

Fig.  85  represents  the  press  commonly  used  in  this 
mode  of  preparing  leather. 

The  committee  on  chemical  arts  of 
the  Societe  d' Encouragement^  reported,  in 
the  bulletin  of  the  Society,  most  favor- 
ably upon  the  processes  of  Vauquelin- 
They  believe  that  the  expense  of  the 
various  methods  used  by  him  does  not  exceed  that  of 
those  ordinarily  employed,  while  a  great  gain  is  secured 
by  tRe  rapidity  of  the  process,  and  the  smaller  quantity 
of  tan  required  by  it. 

Hides  which  are  difficult  to  treat  in  the  ordinary 
mode,  are  tanned  and  prepared  by  this  one  as  easily  as 
any  others.  They  gain  instead  of  losing  weight  in  the 
various  currying  operations,  and  in  the  opinion  of  the 
committee,  and  of  numerous  manufacturers  and  dealers 
in  the  article,  they  exhibit  all  the  evidences  of  being 
equal  or  superior  to  the  very  best  leather. 


vauquelin's  process. 


261 


The  same  committee  again  reported  to  the  Society,  in 
1844,  in  the  following  manner  : — 

"At  the  meeting  of  your  Society,  on  the  11th  day  of 
August,  1841,  a  gold  medal  was  voted  to  M.  Yauquelin, 
for  his  new  tanning  processes.  Since  that  time  he  has 
succeeded  in  overcoming  difficulties  which  seemed  to  be 
insuperable,  and  in  order  to  convince  you  of  the  rapidity 
and  excellence  of  his  methods,  we  present  you  with  the 
results  of  the  experience  we  have  had  of  them. 

"Your  committee,  on  the  9  th  of  January,  1844,  marked, 
at  the  establishment  of  Yauquelin,  one  hundred  calf-skins, 
the  total  w^eight  of  which  amounted  to  398  pounds ;  three 
cow-hides,  weighing  together  15  pounds,  7  oz.^  and  upon 
the  15th  of  January,  1844,  two  horse-hides.  These 
skins  were  found  by  them  to  be  perfectly  tanned,  the 
calf-skins  upon  the  18th  of  March,  the  cow-skins  upon 
the  4th  of  April,  and  the  horse-hides  upon  the  12th  of 
April  of  the  same  year.  One  of  the  calf-skins  having 
been  reserved  by  them  for  special  purposes,  the  ninety- 
nine  remaining  ones  were  found  to  weigh  375  pounds, 
and  the  cow-skins  to  weigh  19  lbs.  13  oz.  The  weights 
of  the  skins,  when  tanned  and  curried,  compared  with 
/  those  found  before  the  tanning,  indicated  that  the  former 
had  suffered  a  slight  loss,  and  that  the  latter  had  gained 
about  27  per  cent. 

"  Thus  the  calf-skins  were  tanned  perfectly  in  sixty- 
eight  days,  the  cow-skins  in  eighty  days,  and  the  horse- 
hides  in  eighty-seven  days ;  while,  if  they  had  been  ex- 
posed to  the  ordinary  processes,  from  twelve  to  fifteen 
months,  or  even  more  would  have  been  required.  These 
results  show  the  astonishing  rapidity  of  the  process  and 
the  skins  themselves  can  be  seen  at  the  Exposition  of 
Products  of  Industry,  where  all  can  convince  themselves 
of  their  thorough  tanning  and  excellent  quality." 


.262 


vatjquelin's  process. 


An  officer  of  the  French  army,  Col.  Chompre,  gives 
ihe  following  notes  of  his  experience  in  the  use  of  Vau- 
quelin's  leather : — 

^^1.  A  piece  of  calf-skin,  forming  a  patch  on  a  pair  of 
trowsers,  which  were  ridden  in  by  a  dragoon  every  day 
for  eight  months,  was  found  at  the  end  of  that  time  in 
a  perfect  state,  and  as  pliable  as  at  first. 

Another  piece  treated  in  the  same  way  for  four 
months,  and  exposed  to  constant  friction,  was  equally 
uninjured. 

"2.  A  number  of  pairs  of  calf-skin  boot-legs  w^ore 
exceedingly  well,  preserving  their  firmness  and  pliability 
without  any  unusual  care  being  used  for  their  preserva- 
tion. 

"  A  pair  of  boots  with  ordinary  tops,  and  with  soles 
made  of  the  tail  part  of  the  horse-hides,  was  worn  by  a 
non-commissioned  officer,  who  generally  wears  out  a 
number  of  shoes.  These  are  now  in  a  perfect  state,  and, 
according  to  his  account,  have  lasted  as  long  as  two 
pair  of  ordinary  soles. 

Five  other  pairs  of  soles  of  shoes  given  to  lancers, 
who  wear  out  a  great  many  in  service,  are  in  an  excel- 
lent state  of  preservation. 

"  3.  The  blackened  leather,  used  for  belts,  girths,  and 
stirrup  straps,  has  also  worn  well. 

"  The  conclusions  of  the  repoxt  of  the  administrative 
council  of  the  regiment  are,  that  the  leather  submitted 
to  and  tried  by  them,  was  superior  to  any  which  had 
before  come  under  their  notice." 


f 


CHAPTER  XVII. 

ACCELERATINa  PROCESSES. 

Numerous  processes  have  been  devised  for  shortening 
the  time  of  tanning.  Their  relative  merits  must  be  de- 
termined by  the  experience  of  the  tanner ;  and  we  there- 
fore present  detailed  descriptions  of  those  which  are 
seemingly  worthy  of  notice.  As  a  general  rule,  the  gain 
in  time  is  at  the  expense  of  the  quality  of  the  leather. 

BERENGER  AND  STERLINGUE'S  PROCESS. 

This  process,  patented  in  1842,  obviates  the  inconve- 
niences attending  the  old  methods  of  tanning,  particu- 
larly in  the  separation  of  hair  from  the  skins.  Its  object 
is  to  reduce  the  time  occupied  in  tanning,  often  amount- 
ing to  sixteen  months,  within  the  reasonable  limits  of 
from  four  to  five  months,  thus  avoiding  the  extreme  of 
allowing  too  short  a  duration  for  a  process  which,  to  be 
successful,  must  be  more  or  less  gradual  and  prolonged. 

When  skins  are  deposited  in  the  vats,  with  water  and 
layers  of  tan  in  the  ordinary  quantities,  the  infusion 
formed  is  usually  found  to  indicate  25  degrees  of  the  hy- 
drometer. In  proportion  as  the  combination  between 
the  gelatine  and  tannin  progresses,  the  strength  of  the 
liquid  diminishes,  until  after  four  months  of  contact,  the 
hydrometer  stands  at  about  8  degrees.  At  the  end  of 
this  time,  the  skins  are  deposited  in  fresh  vats,  and  this 


264 


ACCELERATING  PROCESSES. 


change  is  repeated  a  third  and  often  a  fourth  time,  at 
every  interval  of  four  months,  the  hydrometer  sinking 
successively  each  time,  from  25  degrees  to  about  10,  12, 
and  15.  Thus,  the  introduction  of  tannin  into  the  sub- 
stance of  the  skins,  becomes  gradually  more  and  more 
difficult  and  slow,  owing  to  the  increased  obstacles  to  the 
penetration  into  the  tanned  surfaces.  The  knowledge 
of  these  facts  induced  the  inventors  to  devise  means  of 
tanning  which  should,  unlike  those  ordinarily  used,  keep 
the  skins  in  contact  with  infusions  gradually  and  con- 
stantly increasing  instead  of  diminishing  in  strength. 
For  this  purpose  they  placed  a  wooden  cylinder  in  the 
vats,  through  which  the  infusion  could  be  removed  by 
pumps  and  replaced  by  fresh  and  stronger  liquid  when 
necessary.  They  succeeded,  by  these  means,  in  tanning 
in  a  comparatively  short  time,  and  in  avoiding  the  re- 
newal of  the  contents  of  the  vats;  but  the  proceeding 
was  not  yet  sufficiently  perfected  to  give  it  the  necessary 
precision  and  certainty. 

Eighty  tubs-full  of  water  are  required  to  moisten  a 
freshly  filled  pit,  the  tan  absorbing  much  the  largest 
portion  of  it,  but  only  about  ten  tubs  of  infusion  can  be 
pumped  out  unless  the  pit  is  pressed  and  drained,  which 
injures  the  hides  and  alters  their  relative  position,  so  as 
to  diminish  the  value  of  the  leather.  In  fact,  the  simple 
withdrawal  of  the  amount  of  fluid  above  stated,  leaves 
the  surface  of  the  pit  sunken  and  disordered. 

To  avoid  this  difficulty,  Berenger  and  Sterlingue 
attempted  successfully,  and  with  good  results,  to  remove 
the  old  infusion  from  the  pits,  at  the  same  time  that  it 
was  exactly  replaced  by  the  introduction  of  fresh  and 
stronger  liquid;  but  the  mode  adopted  by  them  was 
deficient  in  regularity  and  certainty,  and  it  became 
necessary  to  devise  better  means  for  the  attainment  of 


ACCELERATING  PROCESSES.  2G5 

their  object.  For  this  purpose,  they  provided  a  row  of 
vats  with  wooden  cylinders,  which  were  connected  above 
at  a  depth  of  six  inches  below  the  surface  of  the  pits,  by 
means  of  a  pipe  passing  from  one  to  another,  and  which 
communicated  below,  by  means  of  a  perforated  tube, 
with  the  open  space  of  a  false  bottom  in  the  pit.  By 
means  of  this  arrangement,  it  was  only  necessary  to 
open  a  cock  of  fresh  water  into  the  weakest  pit,  to  enable 
the  fluid,  which  had  no  other  means  of  escape  when 
this  was  filled,  to  traverse  the  whole  range  of  pits,  filling 
each  one,  from  the  weakest  to  the  strongest,  in  succession, 
before  it  was  possible  for  any  of  it  to  enter  the  next  one. 

We  will  now  suppose  a  series  of  eight  pits  to  be  thus 
arranged,  each  one  provided  with  its  cylinder,  opening  by 
a  perforated  tube  into  the  false  bottom,  and  connecting 
with  the  cylinder  of  the  next  pit  at  a  depth  of  six  inches 
below  the  surface.  Hides  are  then  stratified  with  tan 
in  the  end  pit,  and  water  is  poured  into  it  in  the  ordinary 
manner.  After  from  fifteen  to  twenty-one  days,  a  second 
pit  next  to  the  first  is  filled  with  the  dry  tan  and  skins, 
and  since  80  tubs-full  of  water  were  required  for  the 
saturation  of  the  first  one,  the  same  quantity  of  a  stronger 
infusion,  properly  graduated,  is  poured  into  the  first  pit, 
and  this  liquid  descending,  drives  before  it  and  takes  the 
place  of  that  originally  contained  in  it,  which  has  then 
no  other  means  of  escape  than  to  pass  out  into  the  second 
pit  through  the  communicating  pipe,  in  quantities  exactly 
proportioned  to  those  which  enter  the  first  one.  Fifteen 
or  twenty  days  after  this  operation,  it  is  repeated  in  the 
same  way,  a  stronger  infusion  being  introduced  into  the 
first  pit  for  the  purpose  of  filling  the  third  one  with  the 
liquid  contents  of  the  second,  and  the  second  with  those 
of  the  first.  The  same  proceeding  is  repeated  at  the  same 
intervals  until  the  eighth  and  last  pit  is  filled. 
18 


266 


ACCELERATING  PROCESSES. 


The  communicating  pipe  is  then  closed,  the  infusion 
is  pumped  from  the  first  pit,  and  the  leather  taken  out 
to  dry,  a  fresh  supply  of  hides  and  of  tan  being  deposited 
in  this,  which  has  now  become  the  eighth  pit  of  the  series. 
The  one  which  was  before  second,  being  now  first,  is  to 
be  supplied  with  80  tubs-full  of  strong  infusion. 

Thus,  by  this  process,  one  application  of  tan  is  alone 
required,  the  pits  are  not  changed  until  the  leather  is 
finally  removed  from  them,  and  a  great  economy  of  time 
and  labor  is  secured.  Its  duration  is  generally  from  four 
to  six  months. 

Four  months'  exposure  in  eight  pits  is  sufiicient,  if  the 
strong  infusion  is  added  every  fifteen  days,  but  if  the 
operation  seems  to  be  progressing  too  rapidly,  the  inter- 
val may  be  lengthened  to  three  weeks  or  a  month,  in 
which  case,  from  six  to  eight  months  will  be  occupied. 
The  number  of  pits  may  be  increased  or  diminished  at 
will.  One  hundred  and  twenty  pits  could  even,  were  it 
desirable,  be  placed  in  connection  with  each  other,  which 
would  require,  after  the  perfection  of  the  leather  in  one 
of  them,  that  one  pit  should  be  daily  emptied  of  its  con- 
tents, and  refilled  with  fresh  skins  and  tan,  80  tubs-full 
of  strong  infusion  being  at  the  same  time  poured  into 
the  oldest  one. 

The  infusion  for  watering  the  pits  is  prepared,  or 
rather  renovated,  in  the  following  manner: — 

As  the  leather  is  taken  out  to  dry,  the  infusion  from 
the  same  pit  is  transferred  to  a  set  of  vats  which  are 
especially  provided  for  the  purpose,  and  which  are  like 
those  used  to  furnish  the  liquor  for  tan  baths. 

These  infusions  are  lixiviated  as  above  described,  and 
a  sufficient  quantity  of  fresh  tan  is  mixed  with  them 
to  give  the  requisite  strength.  Thus,  if  the  liquid  be 
only  at  30  degrees  of  strength,  and  is  required  to  reach 


ACCELERATING  PROCESSES. 


267 


60  degrees,  it  is  placed  in  a  large,  raised  reservoir,  which 
connects  with  a  trough.  This  trough  communicates  by 
means  of  a  tube  with  a  second,  a  third,  and  a  fourth 
trough  below  each  other,  all  of  which  have  pipes  running 
longitudinally  along  their  bottoms.  Steam  is  now  passed 
along  these  tubes  so  as  to  heat  the  infusion  which  passes 
successively  through  the  troughs,  and  to  concentrate  it 
to  any  desired  point,  so  as  to  increase  its  strength  and 
deprive  it  of  the  fatty  matter  and  gallic  acid  which  it 
may  have  acquired  in  its  passage  through  the  pits.  It 
is  finally  let  off  by  a  stopcock  into  a  reservoir  below, 
where  it  cools,  and  is  in  a  fit  condition  to  be  poured  into 
the  pits. 

The  same  system  of  continuous  tanning  is  applied  by 
the  authors  to  baths  of  tan-liquor.  The  skins  are  not, 
however,  daily  transferred  from  the  vat  containing  the 
weaker  liquor  to  that  of  the  stronger,  as  in  the  ordinary 
method,  but  are  placed  upon  horizontal  shelves  adapted 
to  each  vat,  and  are  not  taken  out  until  ready  for  the 
tanyard;  the  liquor  itself  being  passed  from  vat  to  vat, 
as  in  the  pits.  In  the  same  way  it  may  be  made  to  re- 
place the  old  system  of  tanning  the  skins  by  floating 
them  in  tan  and  water.  In  that  process,  the  skins,  in- 
fusion, and  tan,  are  all  thrown  together  into  the  vats, 
and,  after  a  time,  the  skins  are  taken  out,  the  infusion  is 
drained  off  from  the  tan,  and  replaced  in  the  same  vats 
with  the  skins  and  fresh  bark,  the  operation  of  change 
being  frequently  repeated  until  complete  tanning  is 
efiected.  By  the  present  mode,  these  repeated  removals 
are  not  necessary,  it  being  sufficient  to  introduce  fresh 
liquor  into  the  oldest  vat  of  the  series,  and  to  keep  it 
constantly  full,  so  that  the  others  will  be  filled  in  suc- 
cession.   The  tanning  will  be  more  complete,  regular, 


268  ACCELERATING  PROCESSES. 

rapid,  and  economical;  all  the  labor  necessary  in  the 
other  process  being  saved. 


Fig.  86. 


a.  Skins  A,  placed  from  head  to  tail,  Ucross  horizontal 
crosspieces  and  resting  upon  them  without  touching 
each  other. 

h.  Exhibits  the  bottom  of  the  pit,  with  the  false  bottom 
taken  out;  and  c  shows  the  latter  in  place. 

d.  Tubes  in  the  bottoms  of  the  pits,  pierced  with  holes 
to  receive  the  infusion.  Their  vertical  parts,  e,  are  not 
pierced,  but  conduct  the  fluid  upwards  from  the  bottom 
of  one  vat  to  the  top  of  the  next  one.  Their  upper  ex- 
tremities turn  horizontally  into  the  adjoining  pits,  so  that 
that  they  cannot  communicate  excepting  through  these 
tubes. 

g.  Horizontal  tube,  connecting  vat  No.  7,  with  No.  1. 


ACCELERATING  PROCESSES. 


269 


As  all  the  vats  communicate,  fluid  poured  into  one, 
readily  passes  through  all. 

i.  Cock,  to  prevent  connection  between  Nos.  1  and  7, 
when  it  is  not  desired. 

Jc.  False  bottom. 

L  Arrows,  indicating  the  direction  of  the  motion  of 
infusion  from  7  to  6,  etc. 

Figs.  88  and  89.  Series  of  pits.  1,  2,  3,  4,  5,  6,  pits, 
forming  a  series. 

Fig.  88. 


a.  Skins  deposited  in  pit,  alternating  with  beds  of 
tan. 

h.  View,  or  plan  of  pits,  with  the  false  bottoms  re- 


Fig.  89. 


e 

(1)  I: 

moved,  and  showing  tubes  curved  and  pierced  with 
holes  in  this  part  alone;  the  vertical  portion  of  the 
tube  passing  up  and  turning  over  under  the  surface,  into 
the  next  pit. 

c.  Plan  of  pits  with  the  false  bottoms  in  place,  above 
the  tubes. 


270 


ACCELERATING  PROCESSES. 


i.  Arrow,  showing  the  movement  of  fluid  from  one 
pit  to  another. 

Jc,  Bungs,  or  stoppers,  used  when  necessary,  to  pre- 
vent the  passage  of  fluid. 

L  False  bottoms,  cullendered. 

Fig.  90. 


Figs.  90  and  91.  Apparatus  for  regenerating  old  tan- 
liquor,  and  concentrating  it  to  the  desired  strength. 


Fig.  91. 


a,  h,  c,  d.  Troughs,  placed  one  above  the  other,  so  that 
the  infusion  in  a  runs  down  into     into  c,  and  into 
through  the  tubes     h' ,  h",  h'",  with  the  stopcocks,  o,  o', 
o",o'  . 

At  the  bottom  of  each  trough  is  a  serpentine  tube 
extending  over  the  whole  surface,  as  seen  in  the  plan. 
The  vapor  enters  each  tube  upon  opening  the  stopcocks 

s',      s'",  in  the  tube  Z. 


ACCELERATING  PROCESSES. 


271 


e.  Reservoir,  in  which  the  liquor  to  be  purified  is  first 
placed.  It  escapes  from  this  through  the  tube  into 
the  first  trough.  When  this  is  full,  the  fluid  still  run- 
ning from  the  reservoir,  the  cock  o  is  opened,  and  the 
warm  and  already  partly  concentrated  fluid  runs  into 
reservoir  h,  and  so  on  successively,  until  the  concentrated 
liquor  passes  through  the  cock  o""  into  a  trough  in  which 
it  is  allowed  to  cool. 

/.  Escape-pipe,  conducting  the  condensed  water  and 
waste  vapor  into  the  open  air. 

p.  Pipe,  for  the  entrance  of  steam. 

The  drawings  represent  only  six  and  seven  elements 
of  the  series  of  pits  and  vats,  while  reference  has  been 
had  in  the  text  to  eight. 

squire's  process. 

This  process,  patented  in  1844,  consists  in  depositing 
the  skins  in  a  horizontal  wooden  cylinder,  which  is  made 
to  revolve  slowly,  under  the  surface  of  hot  tan-liquor,  so 
as  to  insure  constant  agitation  of  the  hides  and  skins, 
and  perfect  exclusion  of  air. 

rig.  92  represents  a  transverse  vertical  section  of  the 

Fig.  92. 


272 


ACCELERATING  PROCESSES. 


apparatus,  as  placed  in  the  vat :  a,  wooden  drum,  12  feet 
long  and  7  feet  in  diameter,  lined  with  ridges,  and  divided 
into  four  compartments  by  the  partitions  5,  h,  which  are 
composed  of  wooden  staves,  or  bars  with  open  spaces 
between  them.  Hot  ooze,  and  some  of  the  tanning  ma- 
terial are  then  introduced  with  the  prepared  hides 
through  a  water-tight  door  c.  The  vat  should  be  deep 
enough  to  admit  the  submersion  of  the  whole  cylinder, 
which  is  to  be  kept  in  uninterrupted  motion,  at  the  rate 
of  six  or  seven  revolutions  per  minute;  and  for  this  pur- 
pose its  axle  d,  resting  upon  upright  supports,  is  turned. 

This  is  really  an  accelerating  process,  for  the  use  of 
hot  ooze,  and  the  continuous  contact  of  the  skins  with 
the  tan-liquor,  shorten  the  time  for  complete  tanning  to 
two  weeks.  Moreover,  it  permits  the  use  of  divi-divi, 
catechu,  and  other  readily  oxidizable  tanning  materials, 
which,  when  used  in  open  vats,  color  the  leather  and 
render  it  unsalable.  The  access  of  air  in  this  process 
being  limited,  this  disadvantage  is  avoided. 

The  ooze  spends  its  force  very  rapidly,  and  must  be 
replaced  by  fresh  hot  liquor  as  fast  as  it  becomes  ex- 
hausted. 

TANNING  BY  MECHANICAL  PRESSURE. 

This  ingenious  method,  proposed  by  Spilsbury,  although 
attended  by  good  results,  has  not  been  as  successful  as 
was  originally  anticipated. 

The  inventor  proposes  to  avoid,  by  his  new  arrange- 
ments, the  deficiencies  of  the  ordinary  processes,  in  which 
skins,  impregnated  with  water,  are  exposed,  under  very 
unfavorable  circumstances,  to  weak  tan  infusions. 

The  hides,  after  being  carefully  depilated,  and  pre- 
pared, and  having  all  the  holes  sewed  up,  so  as  to  render 


ACCELERATING  PROCESSES. 


273 


them  water-tight,  are  tightly  stretched,  by  means  of 
clamps,  upon  rectangular  wooden  frames. 

The  frame,  on  which  the  hide  is  stretched,  is  exactly 
overlaid  by  another  similar  frame,  which  is  to  be  screwed 
down  so  as  to  confine  the  edges,  and  make  them  water- 
tight. Another  hide  is  stretched,  as  before,  over  the 
upper  ledges  of  this  second  frame,  and  a  third  frame 
screwed  down  upon  it,  as  in  the  first  instance,  and  the 
whole  three  securely  bolted  together  by  means  of  clamps, 
so  as  to  form,  as  it  were,  a  water-tight  vat.  The  frames 
are  then  set  upright,  and  the  ooze  allowed  to  flow  into 
the  space  intervening  between  the  two  skins,  through  a 
pipe  leading  into  it  from  a  reservoir  above.  A  hydros- 
tatic pressure  is  thus  maintained,  and  the  liquid  column 
forces  the  ooze  through  the  structure  of  the  hides  by 
slow  infiltration,  and  thus  brings  all  parts  in  direct  con- 
tact with  tannin. 

There  must  be  a  stopcock  in  the  bottom  of  the  vat 
to  allow  the  escape  of  confined  air  as  the  ooze  enters,  and 
the  exit  of  the  spent  liquor  at  the  completion  of  the 
tanning;  but  care  must  be  taken  to  close  it  when  the 
vats  are  full  of  liquid,  and  in  operation.  There  must 
also  be  a  stopcock  in  the  pipe  leading  from  the  reservoir 
to  the  vat,  so  as  to  shut  off  the  communication  when  the 
process  is  finished. 

The  exhausted  liquor  is  let  off  through  the  stopcock, 
and  replaced  by  fresh,  and  as  soon  as  the  skins  are  com- 
pletely tanned,  the  frames  are  taken  apart,  the  edges  of 
the  hides  pared  off,  and  the  leather  dressed  in  the  usual 
manner.  The  process  is  rapid,  but  its  duration  varies  in 
accordance  with  the  amount  of  pressure,  the  strength  of 
infusion  used,  and  the  kind  and  quality  of  the  skins. 
The  necessity  of  clipping  and  sewing  the  skins  causes 
more  or  less  loss  of  material. 


274 


ACCELERATING  PROCESSES. 


The  above  process  has  been  improved  by  two  modifica- 
tions, one  of  Wm.  Drake,  and  the  other  of  Mr.  Chaplin : 
Drake's  process  consists  in  giving  the  hides,  prepared  as 
usual,  an  incipient  tanning  by  immersion  in  a  weak  ooze. 
After  the  necessary  handling,  they  are  taken  out  and 
sewed  together  at  the  edges,  grain  side  within,  in  pairs 
so  as  to  form  water-tight  bags,  with  small  holes  at  the 
ends,  for  the  admission  of  the  tan-liquor.  The  bags  are 
then  suspended,  by  means  of  loops,  between  two  upright 
wooden  racks,  to  prevent  bulging  when  full.  The  cold 
ooze  is  then  introduced  through  a  funnel,  and  by  keeping 
the  bag  distended,  creates  a  pressure,  which  causes  the 
liquid  to  infiltrate  through  the  skin. 

The  fluid,  passing  through  is  received  in  a  vessel  be- 
neath, and  returned,  as  it  accumulates,  to  the  sack.  To- 
wards the  close  of  the  operation,  when  the  skins  become 
firm  and  hard,  the  temperature  of  the  room,  previously 
well  ventilated,  is  raised  from  68°  to  149°  F.,  and  this 
temperature  is  maintained  until  they  begin  to  darken  in 
places,  and  the  liquid  ceases  to  lose  strength,  when  they 
are  taken  down,  are  emptied  of  their  contents,  and  pre- 
pared in  the  usual  manner. 

The  elevation  of  temperature,  by  causing  the  evapora- 
tion of  the  liquid  on  the  external  surfaces  of  the  skins, 
promotes  the  infiltration  of  the  ooze.  To  prevent  indenta- 
tions, by  prolonged  contact  with  the  wooden  bars,  the 
position  of  the  bags  should  be  occasionally  shifted.  By 
this  process  it  is  said  that  a  skin  can  be  as  well  tanned 
in  ten  days,  as  it  can  be  by  the  old  one  in  ten  months ; 
but  as  to  the  quality  and  durability  of  the  leather,  we 
cannot  speak  definitely,  except  as  to  its  appearance, 
which  is  very  favorable. 

Mr.  Chaplin  proposes  to  lay  the  bags  in  an  inclined 


ACCELERATING  PROCESSES. 


275 


position,  and  to  turn  them  frequently^  so  as  to  equalize 
the  tanning  of  the  hides. 

Another  modern  improvement,  consists  in  combining 
the  infiltration  process  with  the  old  Danish  method  :  that 
is,  the  bags  filled  with  ooze,  are,  during  the  action  of  the 
hydrostatic  pressure,  to  ke  kept  immersed  in  the  tan- vat. 

The  chief  objection  to  the  infiltration  process,  is  the 
unequal  permeability  of  the  hides,  as  some  portions  im- 
bibe the  ooze  liquor  more  readily  than  others.  The  pro- 
longed distension  of  the  hides  is  also  liable  to  weaken 
their  structure,  and  consequently  depreciate  the  quality 
of  the  leather.  The  precaution  of  modifying  the  inter- 
nal pressure,  by  suspending  the  bags  between  wooden 
supports,  only  partially  remedies  the  defect ;  for  the  por- 
tions protruding  between  the  spaces  are  still  liable  to 
injury  from  unequal  pressure.  The  laying  of  the  bags 
in  an  inclined  position,  and  turning  them  frequently,  is 
an  improvement  upon  the  old  process,  but  does  not  in- 
sure uniformity. 

John  Cox,  of  London  [Rep.  Pat,  Invent.  1845),  pro- 
poses to  equalize  the  distension  by  suspending  the  bags 
in  a  coarse  canvas  casing,  instead  of  wooden  racks.  The 
porous  texture  of  this  material  will  allow  the  easy  pas- 
sage of  the  infiltrating  liquor,  while,  at  the  same  time, 
by  its  ready  adaptation  to  the  surface  of  the  bags,  it 
sustains  them  firmly,  and  with  a  uniform  pressure. 

The  advantage  of  Spilsbury's  process,  arising  from 
the  unequal  permeability  of  the  hides,  is  said  to  be 
obviated,  by  an  improvement  made  by  J.  F.  Knowlis, 
which  is  as  follows  : — 

The  hides  are  suspended  in  an  air-tight  vessel,  of  capa- 
city somewhat  larger  than  their  dimensions,  and  for  this 
purpose  it  is  lined  near  the  top  with  hooks.  The  hides 
are  hung  at  regular  intervals,  and  kept  distended  by 


276 


ACCELERATING  PROCESSES. 


means  of  weights  attached  to  their  lower  ends.  In  the 
upper  portion  of  the  vessel,  or  vat,  is  an  opening  with  a 
movable  cover,  for  the  entrance  of  the  workman.  In 
the  side  and  near  the  top,  is  a  tube  with  a  stopcock  and 
coupling  screw,  for  connecting  with  an  air-pump ;  and  in 
a  corresponding  position  on  the  opposite  side,  is  a  similar 
tube  for  the  admission  of  air,  to  create  external  pressure  as 
may  be  required.  The  tanning  liquid  having  been  intro- 
duced until  it  reaches  above  the  hides,  the  vessel  is  her- 
metically closed,  and  then  exhausted  of  air  by  means  of 
the  air-pump.  As  soon  as  a  vacuum  is  obtained,  the  con- 
tents of  the  vat  are  left  in  repose  for  a  day  and  night, 
after  which  the  tanning  liquor  must  be  drawn  off,  and 
the  apparatus  allowed  to  remain  empty  for  two  or  three 
hours,  to  permit  the  entrance  of  the  air.  This  manipu- 
lation is  repeated  several  times,  or  until  the  hides  are 
sufficiently  tanned.  The  ooze  must  be  renewed  after 
each  exhaustion  of  the  vessel,  and  the  first  liquid  should 
be  weak,  but,  as  the  operation  proceeds,  its  strength  must 
be  gradually  increased. 

This  means  of  promoting  hydrostatic  pressure,  by  the 
aid  of  a  vacuum,  really  accelerates  the  impregnation 
of  the  hides  with  tannin ;  and  the  process  is  said  to  be 
eligible,  both  as  regards  quality  of  leather,  and  economy 
of  time  and  labor.  The  air  being  withdrawn  from  the 
pores  of  the  skin,  its  resisting  action,  which  prevents  the 
rapid  penetration  of  the  ooze  into  the  skin,  is  over- 
come. 

Poole  has  announced  a  vacuum  process,  very  similar 
to  the  preceding,  except  that  the  preliminary  treatment 
in  the  lime  liquor  is  also  accelerated  by  atmospheric 
pressure.  The  prepared  hides  are  then  tanned  as  by 
Knowlis's  method,  and  ultimately  dried  in  an  exhausted 
chamber,  which  is  traversed  by  pipes  heated  with  steam. 


ACCELERATING  PROCESSES. 


277 


The  apparatus  which  he  employs,  is  shown  by  Fig. 
93,  which  exhibits  the  vat  from  which  the  air  is  ex- 


Fig.  93. 


haunted  by  means  of  the  air-pump,  seen  above  it.  The 
trap-door  is  held  down,  when  closed,  by  the  bar,  which 
is  fastened  by  screws  and  nuts. 

Instead  of  having  an  air-pump  attached  to  each  vat, 
a  central  one,  connecting  by  tubes  with  all  the  vats,  can 
be  substituted ;  or,  still  better,  a  movable  one  may  be  em- 
ployed, which  can  be  accurately  adjusted  to  each  separate 
vessel. 

A  space  of  from  six  to  eight  inches  between  the  surface 
of  the  liquid,  and  the  top  of  the  vessel,  will  be  quite 
sufficient  room  for  the  evolution  of  air  bubbles  which  oc- 
curs from  the  former  when  the  vacuum  is  being  formed. 

The  hides  are  stretched  upon  wooden  frames,  and  sus- 
pended vertically  in  the  vat,  free  from  contact  with  each 
other,  and  there  left  undisturbed  until  the  completion  of 
the  process. 

At  the  end  of  forty-eight  hours,  during  which  the 
vacant  space  in  the  upper  part  of  the  vessel  has  been 
kept  exhausted,  the  liquid  is  drawn  off  through  a  stop- 


278 


ACCELERATING  PROCESSES. 


cock  in  the  bottom,  and  the  skins  exposed  to  the  air  for 
half  an  hour  in  winter,  and  quarter  of  an  hour  in  sum- 
mer, before  the  vat  is  refilled  with  a  stronger  tan-liquor 
than  that  first  employed.  After  a  like  interval,  the  ope- 
ration is  repeated  a  third  time  with  liquor  of  increased 
strength ;  and  so  on  until  the  tanning  is  completed. 

In  this  improved  method,  the  skins  being  properly 
placed  in  the  vats,  are  first  exposed  to  the  action  of  lime- 
water  under  a  vacuum,  so  as  to  deprive  them  of  hair. 
The  second  bath  consists  of  weak  tan  infusion,  soured  by 
sulphuric  or  muriatic  acid,  for  the  purpose  raising  them, 
the  operation  being  conducted  as  before,  and  as  in  all  the 
succeeding  ones  by  the  aid  of  the  vacuum.  The  third 
bath  is  composed  of  tan-liquor,  also  of  a  strength  of  one- 
fourth  of  a  degree.  As  this  will  probably  be  reduced  by 
its  loss  of  tannin,  to  one-eighteenth  of  a  degree,  the  next 
bath  may  be  increased  in  strength  to  that  of  a  half  de- 
gree, and  so  on  with  the  succeeding  ones,  a  larger  amount 
of  tanning  matter  equivalent  to  a  quarter  or  fifth  degree 
more  of  the  areometer,  being  applied  each  time,  until,  in 
the  final  operations,  the  infusion  rises  to  four,  five,  or  six 
degrees  of  strength. 

Plot  water  is  to  be  used  for  leeching  the  tan. 

The  exhausted  liquors  can  be  kept  for  future  processes 
less  advanced  than  those  for  which  they  were  employed, 
their  strength  being  increased  to  the  proper  point  by 
additions  of  tan. 

The  figure,  referred  to  in  the  text,  represents  a  wooden 
vat,  but  one  built  of  masonry  may  be  employed  with  an 
air-tight  cement  in  the  interior,  and  covered  with  a 
wooden  or  metallic  top,  so  adjusted  as  to  prevent  the 
admission  of  air.  As  the  expansion  of  the  pores  of  the 
skins  would  be  prevented  by  atmospheric  pressure  in  the 
earlier  part  of  the  process,  it  must  not  be  employed  until 


ACCELERATING  PROCESSES.  - 


279 


near  the  completion  of  the  tanning,  or  the  last  three 
liquors. 

The  vat  may  be  left  open  for  twenty-four  hours ;  and 
this  exposure  to  air  may  be  extended,  during  the  last 
bath,  to  forty-eight  hours. 

From  twenty  to  twenty-five  days  are  generally  suffi- 
cient for  tanning  calf-skins  by  this  method,  and  thirty- 
five  days  for  the  thickest  ox  or  cow  hides. 

HANNOYE's  PROCESS. 

Another  method,  analogous  in  principle  to  the  pre- 
ceding, consists  in  producing  an  equable  and  active 
filtration  of  tan-liquors  through  the  skins,  while  they 
are  exposed  to  pressure,  the  kind,  temperature,  strength, 
and  mode  of  employment  of  which  can  be  varied  at  will. 
For  this  purpose,  the  filter-press  of  Real,  with  some 
modifications,  is  made  use  of,  not  merely  with  the  inten- 
tion for  which  it  has  before  this  been  employed,  of  ex- 
tracting the  active  principles  of  bark,  but  as  a  direct 
agent  in  the  tanning  process  itself;  the  skins  being  stra- 
tified in  it  with  layers  of  bark,  and  the  extraction  of  the 
tannin,  and  the  absorption  of  it  by  the  skins,  being  both 
efiected  under  pressure,  and  without  contact  of  air.  The 
apparatus,  which  has  been  prepared  upon  the  principle 
of  the  filter-press,  is  provided  like  it,  with  a  tube  having 
air-tight  joints,  by  means  of  which  a  forced  and  uniform 
filtration  is  efiected  by  the  pressure  of  a  column  of  fluid, 
and  the  tube  is  of  such  a  height  that  the  pressure  can 
be  increased  or  diminished  at  pleasure  by  altering  the 
height  of  the  column,  while  the  character  of  the  opera- 
tion can  be  varied  at  will  by  the  employment  of  different 
fluids.  The  pressure  of  the  column  of  fluid  can  be 
directed  alternately  upon  either  the  upper  or  lower  sur- 


280  ACCELERATING  PROCESSES. 

faces  of  the  skins,  by  means  of  tubes  provided  with  stop- 
cocks, and  entering  the  vessel  at  the  top  and  bottom. 

The  inventor  claims  this  new  application  of  the  prin- 
ciple of  the  filter-press,  as  being  entirely  original,  and 
asserts  that,  by  the  employment  of  it,  he  has  been  able 
to  arrive  at  a  perfection,  rapidity,  and  exactitude  of  the 
method  of  tanning,  which  have  not  been  attained  by  any 
other  process. 


Fig.  94. 


Figs.  94,  95,  96.  Vessels  of  a  cylindrical  or  square 
form,  of  a  suitable  capacity  to  hold  the  number  of  skins 

Fig.  95. 


ACCELERATING  PROCESSES. 


281 


intended  to  be  operated  upon,  and  which  are  capable  of 
resisting  a  considerable  pressure.    A  tube  a,  a,  Fig.  94. 


Fig.  96. 


is  attached  to  each,  and  is  proportioned  in  height  to  the 
mode  of  making  pressure  which  is  to  be  adopted,  whether 
it  be  that  of  a  column  of  watery  fluid,  of  mercury,  or  of 
the  hydraulic  piston.  Branch-pipes,  h,  5',  connect  this 
tube  with  the  upper  and  the  lower  part  of  the  reservoir, 
and  the  opening  of  one  or  the  other  of  the  stopcocks 
upon  them,  causes  the  pressure  and  consequent  infiltra- 
tion of  tan-liquor  through  the  skins  to  take  place  either 
from  above  downwards,  or  in  the  opposite  direction. 
A  pipe  with  a  stopcock  e,  allows  the  liquid  within  the 
vat  to  escape. 

"The  reservoir  may  be  composed  of  different  materials. 
It  may  be  constructed  of  solid  masonry,  covered  in  its 
interior  with  lime  cement,  over  which  a  coating  of  tar 
or  of  some  resinous  substance  is  placed,  so  as  to  defend  the 

leather  from  the  action  of  the  Hme.    It  mav  be  made  of 

t/ 

wood,  lined  with  sheet-lead  ]  zinc  or  copper,  well  soldered 
in  all  parts;  or  may  be  composed  of  cast-iron,  lined 
19 


282 


ACCELERATING  PROCESSES. 


throughout  with  lead  or  zinc,  so  as  to  prevent  the  injuri- 
ous effect  of  oxide  of  iron  upon  the  leather.  In  either 
case,  the  rim  of  the  neck  of  the  vessel  consists  of  a  solid 
plate  or  disk  of  metal,  firmly  attached  to  it,  and  a  disk 
of  thick  leather  is  interposed  between  it  and  the  top  or 
lid,  which  is  tightly  fastened  down  by  means  of  screws 
and  nuts  upon  the  plate.  This  top  may  consist  of  thick 
wood  or  of  metal  plate,  also  lined  on  its  lower  surface 
with  sheet-lead  or  zinc.  The  copper  or  leaden  tube  d, 
for  the  column  of  fluid,  is  from  one  to  three  inches  in 
diameter,  and  is  connected  with  the  vessel  by  two  tubes, 
/,  f,  one  entering  it  below  the  lid,  the  other  at  its 
base.  By  opening  the  stopcock  upon  the  upper  tube, 
the  pressure  of  the  fluid  is  made  upon  the  upper  surface 
of  the  skins,  and  in  the  opposite  direction  by  opening 
that  upon  the  lower  tube.  Two  other  cocks,  ^,  g'y  the 
one  proceeding  from  the  lid,  the  other  from  the  lower 
part  of  the  reservoir,  conduct  the  liquid  which  has  tra- 
versed the  skins  into  a  suitable  receptacle,  the  upper  one 
being  left  open  when  the  pressure  is  from  below,  and  the 
lower  one  when  it  proceeds  from  above.  The  skins  are 
stratified  in  the  vat  between  beds  of  tan;  water  alone  is 
usually  employed  for  the  pressure  upon  its  contents,  and 
for  the  extraction  of  the  tannin,  and  the  cocks  for  the 
egress  of  fluid  are  only  left  so  much  open  as  to  allow  it  to 
escape  drop  by  drop. 

"Calf-skins  may  be  tanned  in  twenty  days  by  this 
method,  and  ox-hides  in  sixty  days,  but  the  tanning 
may  be  much  expedited  by  the  following  arrangement. 
Instead  of  simply  stratifying  the  skins  with  layers  of 
bark,  a  framework  of  wood,  with  an  open  space  in 
its  interior,  rather  smaller  than  the  skins,  is  placed 
upon  each  one.  The  interior  of  this  frame  is  filled  with 
tan,  another  skin  is  extended  above  the  frame  thus 


ACCELERATING  PROCESSES. 


283 


filled,  and  is  in  turn  surmounted  by  other  frames  and 
skins  arranged  in  the  same  manner.  To  prevent  the 
fluid  from  being  forced  through  the  spaces  between  the 
outsides  of  the  frames  and  the  walls  of  the  vessel,  these 
are  filled  up  with  mastic,  or  some  impervious  cement  like 
the  fatty  lute  of  chemists,  or  a  mixture  of  tallow  and 
rosin.  A  similar  apphcation  of  lute  is  made  around  the 
edges  of  the  skins,  and  the  weight  of  the  tan  and  frames 
soon  makes  the  cemented  parts  perfectly  tight. 

"After  each  tanning  is  completed,  the  mastic  or  luting 
can  be  taken  off  and  used  for  a  similar  purpose  again. 
Skins  tanned  by  this  last  method  are  as  perfectly  pre- 
pared in  a  few  days,  as  those  which  have  been  exposed 
in  the  pits  for  sixteen  months." 

DANISH  PROCESS. 

This  rapid  method  of  tanning,  by  which  "dressing 
leather"  may  be  made  in  two  months,  is  practised  in 
Brittany  and  elsewhere. 

After  the  skins  have  been  soaked,  fleshed,  freed  from 
hair,  and  rinsed  in  the  ordinary  manner,  they  are  colored 
by  being  barley  and  tan  dressed  like  barleyed  skins. 
They  are  then  sewed  up  into  the  form  of  bags,  aper- 
tures of  about  ten  inches  in  length  being  left,  through 
which  they  are  filled  with  tan  and  water.  These  open- 
ings being  sewed  up,  the  closed  sacks  are  forcibly  beaten 
in  every  part,  for  the  purpose  of  distributing  their  con- 
tents equally  throughout.  They  are  then  deposited  in 
pits  which  should  contain  suflicient  ooze  to  cover  them 
completely ;  these  pits  being  four  and  a  quarter  feet  in 
depth,  the  same  in  breadth,  and  from  eight  and  a  half  to 
ten  and  a  half  feet  long.  When  submerged  in  the  pits, 
planks  heavily  weighted  with  large  stones  or  weights,  are 


284 


ACCELERATING  PROCESSES. 


placed  upon  the  skins^  so  as  to  press  them  down  forcibly 
towards  the  bottom,  and  to  increase  the  penetrating  power 
of  the  infusion ;  and  in  order  that  they  may  not  be  un- 
equally tanned  on  their  different  sides,  these  planks  are 
removed  three  or  four  times  a  week,  and  the  sacks  are 
thoroughly  beaten  and  changed  in  position. 

Skins  prepared  in  this  way  are  supple  and  pliable  like 
crop-leather,  and  have  a  finer  color  than  strong  leather, 
but  they  are  thinner  than  those  made  in  the  ordinary 
way,  owing  to  their  not  swelling  up  by  the  slow  process 
of  feeding,  and  to  the  pressure  from  wdthin  and  without 
to  which  they  have  been  subjected. 

It  is  possible  that  an  improvement  of  this  process,  which 
is  now  the  old  method  combined  with  that  devised  by 
Seguin,  may  offer  many  advantages. 

The  external  and  internal  pressure  mutually  assisting, 
must  certainly  promote  the  introduction  of  tannin  and 
extractive  matter  into  the  tissue  of  the  skins.  It  is, 
however,  doubtful  if  the  durability  and  other  qualities 
of  the  product  are  equal  to  those  of  leather  prepared  by 
more  tedious  processes. 

rotch's  process. 

This  method,  patented  in  France  in  1842,  consists  in 
causing  tannin  to  penetrate  the  skins  by  moistening 
them  with  tan-liquor  upon  one  side,  while  the  water 
which  passes  through  the  pores  is  made  to  evaporate 
upon  the  other,  by  the  application  of  artificial  heat.  By 
this  means  the  greater  part  of  the  tannin  remains  in  the 
leather,  and  the  strength  of  the  liquid  which  acts  on  the 
latter  is  being  continually  increased  instead  of  dimin- 
ished as  in  the  old  method.    Leather  can  thus  be  pre- 


ACCELERATING  PROCESSES. 


285 


pared  as  perfectly  in  ten  days,  as  it  commonly  is  in  ten 
months. 

The  skins,  previously  limed  in  the  usual  manner,  are 
soaked  and  handled  in  a  weak  tan-liquor,  for  the  purpose 
of  raising  and  coloring  them.  After  being  prepared  and 
cleaned,  they  are  then  carefully  examined,  and  if  an}^ 
holes  are  found,  they  are  pieced  and  sewed.  If  it  is  de- 
sired, the  skins  may  be  cut  into  forms  suitable  for  the 
purposes  to  which  the  leather  is  to  be  applied. 

It  is  more  economical  to  work  two  skins  at  a  time,  and 
those  of  equal  size  are  closely  stitched  together  at  the 
edges,  grain  to  grain,  with  tarred  thread,  and  are  sus- 
pended by  cords,  as  seen  in  Fig.  97,  to  the  pegs  5,  5,  5,  5, 


Fig.  97. 


which  project  from  the  bar  a.  This  bar  is  the  top  of  a 
wooden  rack  a,  c,  and  there  is  a  similar  rack  on  the 
other  side  of  the  bag  of  skins,  so  that  the  latter  can  be 
compressed,  not  forcibly,  but  in  such  a  manner  as  to 
make  it  retain  its  shape  when  full  of  fluid,  between  the 


286 


ACCELERATING  PROCESSES. 


two  ranges  of  uprights  which  are  made  to  approach  one 
another  by  screws  e.  An  opening  about  an  inch  in 
length  is  left  in  the  upper  part  of  the  bag,  for  the  recep- 
tion of  the  funnel  through  which  the  tan-liquor  is  poured 
in.  The  funnel  may  be  conveniently  placed  in  the  neck 
or  collar,  seen  in  the  figure  along  side  of  the  rack. 

Fig.  98  represents  a  section  of  a  side  view  of  the  rack, 
and    s  the  pegs  upon  the  head  of  the  rack,  from  which 


the  bag  of  skins  is  suspended.  The  inner  sides  of  the 
central  bars  composing  the  rack  are  hollowed  out  in  the 
form  of  arcs  of  large  circles,  as  seen  in  Fig.  99. 

The  skins  being  thus  suspended,  the  cold  tan-liquor  is 
poured  through  the  funnel  until  the  bag  is  entirely  full. 
After  a  time,  which  varies  in  length  according  to  the 
thickness  and  permeability  of  the  skins,  their  outside 
becomes  moist,  and  the  water  which  filters  through, 
slowly  drops  into  the  gutter  7i,  and  flows  into  a  receptacle 
placed  below  its  spout.  This  liquid,  as  soon  as  it  is  cold, 
may  be  poured  back  into  the  bag  so  as  to  keep  it  con- 


Fig.  98. 


Fig.  99. 


ACCELERATING  PROCESSES. 


287 


stantly  full,  and  the  supply  of  fluid  is  kept  up  from  time 
to  time  in  proportion  as  it  is  lost  by  evaporation  and  by 
draining  off. 

As  soon  as  the  surface  of  the  skins  becomes  firm  to  the 
touch  and  equally  moist  throughout,  the  air  of  the  room 
in  which  the  operation  is  conducted,  and  which  should 
be  provided  with  a  ventilator  to  allow  the  vapor  to  escape, 
must  be  gradually  heated  from  70°  to  150°  F.,  and  kept 
at  this  latter  temperature  until  the  skins  become  firm 
and  hard  in  every  part,  and  assume  a  brown  color,  and 
until  the  liquor  in  the  sacks  ceases  to  diminish  in 
strength.  When  all  this  occurs,  the  skins  are  thoroughly 
tanned.  They  are  then  taken  from  the  frame,  emptied 
of  their  contents,  the  borders  which  have  been  sewed 
are  cut  off,  and  the  skins  are  dried  and  prepared  as 
usual.  During  the  continuance  of  the  process,  care  should 
be  taken  to  change  their  position  frequently,  so  that  the 
bars  of  the  frame  may  not  impress  furrows  or  marks  upon 
their  surfaces,  by  pressing  for  too  long  a  time 
upon  the  same  parts. 

The  time  required  for  tanning  by  this  pro- 
cess, varies  with  the  thickness  of  the  skins, 
their  changes  of  position,  the  strength  of  the 
liquor,  the  regulation  of  the  heat  of  the  apart- 
ment, and  other  circumstances  which  an  expe- 
rienced operator  can  readily  appreciate.. 

Fig.  100  shows  a  section  of  the  rack:  5, 
lower  part  of  the  rack :  c,  c,  bars  of  the  two  racks 
placed  so  as  not  to  be  opposite  to  each  other. 

s.  sjstyder's  process. 

Mr.  Snyder,  of  Ohio,  proposes  to  expedite  the  tanning 
of  skins,  by  making  their  interior  more  accessible  to  tan- 


288 


ACCELERATING  PROCESSES. 


liquor  through  numerous  fine  punctures  made  in  the  sur- 
face. He  performs  this  pricking  or  acupuncture  by  means 
of  an  instrument  with  a  surface  of  fine  needle  points, 
composed  of  from  100  to  300  to  the  square  inch,  accord- 
ing to  the  thickness  and  quality  of  the  skin.  A  hand- 
instrument  struck  by  a  mallet  is  at  present  used,  and 
with  it  a  workman  can  prepare  thirty  or  forty  skins  in  a 
day ;  but  a  cylindrical  machine,  covered  with  steel  points, 
could  easily  be  made,  which  would  prick  a  much  larger 
number. 

Some  skins  require  puncturing  on  the  flesh,  some  on 
the  grain  side. 

It  may  appear  paradoxical  to  recommend  the  perforation 
of  an  article,  the  chief  desideratum  of  which  should  be  its 
imperviousness  to  moisture ;  but  the  operation  is  performed 
while  the  skins  are  in  the  most  soft,  moist,  and  relaxed 
state,  after  they  are  worked  out  of  the  hate,  or  grainer; 
and  when  in  this  condition,  the  fibres  separate  before  the 
points  of  the  instruments  just  as  other  tissues  do  before 
a  pin  or  needle.  This  soft  and  relaxed  substance,  full  of 
indentations,  after  having  been  tanned  and  dried,  will  be 
found  to  be  dense  and  contracted,  and  will  not  exhibit  a 
trace  of  defect  from  the  operation  to  which  it  has  been 
subjected.  These  punctured  orifices  do  not  close,  how- 
ever, immediately  after  the  withdrawal  of  the  instrument 
or  directly  upon  being  tanned,  but  remain  sufficiently 
open  to  admit  the  liquor  into  the  interior  of  the  skins, 
throughout  the  process,  and  until  it  is  quite  completed, 
becoming  only  gradually  obliterated. 

Better  leather  can  be  manufactured  where  this  acu^ 
puncturation  is  resorted  to  than  by  other  means,  for  the 
following  reasons : — 

1.  Because  the  tanning  is  so  accelerated,  and  the  re- 


ACCELERATING  PROCESSES. 


289 


newal  of  the  tan-liquor  necessarily  so  frequent,  that  it 
is  not  exposed  to  the  air  long  enough  to  become  acid. 
It  is  well  known  that  acid  has  an  injurious  effect  upon 
skins,  relaxing  their  pores,  expanding  their  fibres,  en- 
larging the  grain,  and  rendering  the  leather  brittle ;  and 
since  eight  or  ten  days  often  suffice  to  acidify  tan-liquor, 
it  follows  that  the  skins  are  frequently  exposed  to  these 
injurious  influences  in  the  old  processes,  often  for  six  or 
eight  weeks  at  a  time.  These  obstacles  to  tanning  are 
avoided  now,  by  a  method  which  exposes  a  much  larger 
surface  to  the  action  of  the  tan-liquor,  so  that,  being 
rapidly  exhausted  of  tannin,  it  requires  a  renewal  of  the 
tan-liquor  before  sufficient  time  elapses  to  acidify  it. 

2.  Because  by  bringing  the  tannin  at  first  directly  in 
contact  with  the  interior  of  the  structure,  the  chemical 
change  takes  place  there  as  rapidly  as  upon  the  surface; 
so  that  there  is  no  occasion,  as  in  the  old  method,  for  the 
surface  to  be  exposed  so  long  as  to  be  rendered  hard  or 
brittle,  in  order  to  allow  the  solution  to  pass  through  it 
to  the  centre. 

Although  a  very  short  time  is  occupied  in  tanning  by 
this  method,  the  process  may  be  still  further  expedited 
by  the  application  of  hydrostatic  pressure.  For  this 
purpose  it  is  necessary  to  use  a  strong  water-tight  box,, 
made  as  nearly  as  possible  of  the  same  shape  as  the  skins, 
and  having  sides  four  to  five  inches  in  height,  with  a 
groove  running  all  around.  A  layer  of  tan  or  other 
tanning  material  is  deposited  in  the  box,  and  is  moist- 
ened with  a  small  quantity  of  strong  tan-liquor.  The 
skin  is  stretched  over  this,  with  the  grain  side  up,  and 
another  frame,  exactly  of  the  size  of  the  first,  with  a 
continuous  tongue,  which  presses  the  edges  of  the  skin 
into  the  groove,  should  be  placed  on  it.    The  two  boxes 


290 


ACCELERATING  PROCESSES. 


are  held  together  by  screws  and  nuts  at  the  corners.  A 
number  of  these  boxes  are  then  piled  upon  each  other 
in  a  vat  full  of  weak  tan-liquor,  each  one  being  provided 
with  a  flexible  tube  or  hose,  rising  from  above  the  edge 
of  the  skin  to  the  surface  of  the  pit,  so  as  to  allow  the 
egress  of  air. 


CHAPTER  XVIII. 


keasley's  process. 

Mr.  Thomas  Keasley,  of  England,  has  patented  (Janu- 
ary llj  1845)  a  process  founded  upon  his  experience 
that  alternate  immersion  and  removal  of  the  hides  from 
the  ooze,  so  as  to  allow  frequent  exposure  of  them  to  the 
air,  shortens  the  time  of  tanning,  and  improves  the 
quality  and  weight  of  the  latter. 

The  apparatus  consists  of  a  square,  rectangular,  or 
other  conveniently  shaped  framing,  from  which  the  hides 
or  skins  are  suspended  vertically,  in  any  convenient 
manner.  The  dimensions  of  the  framing  from  which 
the  hides  or  skins  are  suspended,  must,  of  course,  corre- 
spond with  the  size  of  the  pit,  so  that  the  frame  belong- 
ing to  each  pit,  and  with  it  the  hides,  may  be  raised  or 
lowered  at  the  discretion  of  the  attendant.  Each  of  these 
frames,  containing  the  hides,  is  distinct  and  separate,  and 
may  be  raised  and  lowered,  separately,  by  manual  labor, 
with  the  assistance  of  a  windlass,  if  required ;  but  it  has 
been  found  more  advantageous  to  connect  two  contiguous 
frames  together,  so  as  to  make  them  counterbalance  each 
other,  and  thus  considerably  diminish  the  labor  of  work- 
ing them.  A  variety  of  means  may  be  devised  for  carry- 
ing this  idea  into  effect,  but  several  plans  are  shown 
which  will  be  found  to  answer  the  purpose. 


292 


keasley's  process. 


"Fig.  101  represents  a  side  elevation,  and  Fig.  102  an 
end  elevation  of  one  plan,  in  which  the  frames  a,  a,  a, 


filled  with  hides,  or  parts  of  hides  5,  5,  are  suspended  from 
the  extremities  of  a  vibrating  beam  or  lever  c,  c,  by 
means  of  chains  or  cords  d.  The  tan-pits  or  vats  e, 
are  shown  in  in  section,  in  both  these  figures.  The  beam 
or  lever  c,  c,  is  mounted  at  /,  in  bearings  firmly  fixed  in 
the  framing  ^,  for  that  purpose,  and  is  worked  up  and 
down  by  means  of  chains  or  cords  h,  which  pass  round 
a  windlass  or  barrel  i,  ^,  below,  and  are  fastened  at  either 
end  to  the  extremities  of  the  vibrating  beam.  On  the 
axle  of  the  windlass,  or  barrel,  is  mounted  a  toothed 
wheel  y,  shown  by  dots  in  Fig.  101;  it  is  driven  by  a 
pinion  Jc,  which  is  fixed  on  the  shaft  Z,  and  is  actuated 
by  applying  power  to  the  said  shaft,  by  means  of  a  winch 
or  otherwise.  It  will  now  be  understood  that  as  the  pin- 
ion Jc,  toothed  wheel  j,  and  barrel  or  windlass  i,  ^,  are 


Fig.  101. 


keasley's  process. 


293 


made  to  revolve,  one  end  of  the  beam  or  lever  c,  c,  will 
be  raised,  and  the  opposite  end  depressed,  by  one  of  the 


Fig.  102. 


ropes  passing  over  and  the  other  under  the  barrel  or 
windlass;  and  by  this  means  one  frame  of  hides  will  be 
lifted  out  of  the  tan  liquor,  while  the  hides  on  the  oppo- 
site one  are  totally  immersed.  This  operation  may  be 
reversed  by  turning  the  winch  in  the  opposite  direction. 
The  ascent  and  descent  of  the  frames  is  assisted  by  the 
forked  guides  m,  m  (see  Fig.  102),  which  work  against 
the  vertical  guide-rods  7i.  At  night,  or  at  other  times, 
when  it  is  necessary  that  the  hides  on  both  frames  should 
be  immersed,  this  object  is  easily  effected  by  unhooking 
from  the  suspending  chains  or  ropes  cZ,  d,  by  means  of  the 
hook  r,' the  frame  that  is  already  immersed,  and  then  al- 
lowing the  other  frame  to  descend  into  the  liquor,  which 
it  will  easily  do  by  its  own  weight.  When  one  of  the 
frames  is  raised,  it  is  kept  elevated  by  merely  placing  a 


294 


keasley's  process. 


leather  or  wooden  block  between  the  teeth  of  the  toothed 
wheel  y,  and  pinion  and  thereby  preventing  them  from 
revolving.  This  stop  fully  answers  the  purpose,  and  is 
more  convenient  than  a  pall  and  ratchet-wheel. 

"Fig.  103  represents  a  side  elevation  of  another  plan 


Fig.  103. 


of  carrying  out  the  counterbalance  principle.  In  this 
plan  the  vibrating  beam  c,  is  suppressed,  and  the  sus- 
pending cords  or  chains  and  the  working  cords  or 
chains  li,  are  united  together,  and  form  the  cords  or 
chains  o,  o,  which  pass  over  pulleys  p,  ^,  at  the  outer 
extremities  of  the  standards  g,  and  down  between  two 
other  pulleys  q,  q,  and  round  the  barrel  or  windlass  i, 
as  in  the  former  instance.  If,  however,  it  is  thought 
more  desirable,  the  pulleys  p,  and  q,  q^  may  be  at- 
tached to  a  beam,  or  the  ceiling  above,  instead  of  the  stand- 
ards g,  g.  The  barrel  %  is  furnished  with  a  toothed 
wheel  j,  and  is  driven  by  a  pinion  precisely  in  the 
manner  explained  in  reference  to  Figs.  101  and  102,  and, 
therefore,  no  further  explanation  will  be  necessary. 
"The  patentee  has  also  shown  a  means  of  raising  the 


keaslet's  process.  295 

frames  containing  the  hides  or  skins,  one  at  a  time.  In 
this  case  the  pulleys  are  fastened,  as  before  mentioned, 
to  a  beam  above ;  the  windlass  or  barrel  being  placed 
below. 

"  Fig.  104  represents  another  plan  of  raising  the  frames. 


Fig.  104. 


In  this  instance,  several  frames  with  the  hides  or  skins 
suspended  vertically,  may  be  raised  at  one  time,  but 
not  upon  the  counterbalance  principle.  The  frames, 
with  the  hides  or  skins,  are  raised  by  means  of  a  rope 
or  cord  s,  s,  s,  which  passes  over  pulleys  t,  t,  affixed 
to  a  strong  beam  ii,  above.  One  end  of  the  rope 
s,  5,  is  firmly  fixed  to  the  beam,  as  seen  in  the  draw- 
ing, and  the  other  end  is  passed  over  the  pulleys  t,  t, 
and  round  a  windlass  at  the  other  extremity  of  the 
beam.  The  suspension  cords  of  the  frames  are  each 
furnished  with  a  pulley  or  block  constructed  in  such 
a  manner  that  it  may  with  facility  be  hooked  on  to,  or 
detached  from  the  rope  5,  5,  according  to  whether  it 
be  required  to  raise  the  frames  containing  the  skins  or 
hides,  or  parts  of  skins  or  hides,  out  of  the  tan-liquor,  or 
to  allow  them  to  remain  immersed.  It  will  be  found  most 
convenient  to  raise  only  one-half  the  number  of  frames 
at  one  time,  leaving  the  remainder  in  the  tan-liquor.  In 
order  to  do  this,  the  rope  s,  s,  is  brought  down  and 
every  other  frame  hooked  on  to  the  rope;  then,  by  turn- 
ing the  windlass  or  barrel,  and  causing  the  rope  s,  s  to 
coil  thereon,  the  frames,  with  the  hides  or  skins,  will  be 
raised  out  of  the  pits,  as  shown  in  the  drawing;  the  other 


296 


keasley's  process. 


frames,  which  are  not  attached  to  the  rope,  remaining 
immersed.  When  the  first  lot  of  skins  have  been  ex- 
posed a  sufficient  length  of  time  to  the  atmosphere,  the 
frames  are  lowered  into  the  liquor  again,  where  they  are 
allowed  to  remain,  by  unhooking  the  pulleys  which 
connect  them  to  the  rope  s,  s;  and  those  which  were 
before  immersed,  are  now  to  be  raised  by  hooking  them 
in  their  turn,  by  means  of  their  pulleys  v,  v,  on  to  the  rope 
s,  5.  If  thought  advisable,  the  counterbalance  principle 
may  be  applied  to  this  arrangement  or  plan  of  raising  and 
lowering  the  frames,  by  merely  employing  an  additional 
rope  s,  s,  passed  over  pulleys  exactly  similar  to  the  one 
shown  in  the  drawing.  One  end  of  this  rope,  also,  should 
be  firmly  attached  to  the  end  of  the  beam  u,  u,  and  the 
opposite  end  to  the  windlass  or  barrel ;  or,  instead  of  two 
ropes,  one  only  may  be  employed,  by  having  it  of  suffi- 
cient length  to  pass  from  the  end  of  the  beam  over  the 
pulleys  ty  t,  round  the  windlass  and  back  again  over  simi- 
lar pulleys  t,  to  the  end  of  the  beam,  so  as  to  present 
a  double  rope,  to  one  part  of  which  the  three  frames  1, 
3,  5,  would  be  suspended,  while  the  other  frames  2,  4, 
would  be  suspended  from  the  other  part.  Now  if  a 
double  rope  s,  is  employed,  there  will  be  no  necessity  to 
detach  the  frames  from  the  ropes.  The  pulleys  v,  are 
merely  made  to  run  freely  on  the  said  ropes,  and  are  not 
required  to  be  constructed  so  as  to  hook  on,  as  above- 
mentioned.  It  will  now  be  understood,  that  if  the 
counterbalance  principle  is  carried  out  in  this  manner, 
one  set  of  frames  will  be  elevated,  while  the  others  are 
immersed;  and  the  action  of  lowering  one  set  will  raise 
the  other ;  that  is,  when  the  windlass  is  unwinding  the 
rope  to  lower  one  set,  it  is  at  the  same  time  winding 
up  the  other  rope,  and  thereby  raising  those  frames  con- 
nected with  it." 


KEASLEY'S  PROCESS. 


297 


"Fig.  105  represents  another  plan  of  raising  the  frames. 
In  this  j)lan  a  traveUing  windlass  is  employed^  which 


Fig.  105. 


■1 

■  |- 

11 

[ill  1 1 1  , 

may  be  made  to  traverse  a  railway,  or  floor,  constructed 
on  the  top  of  the  beam  u,  above  the  frames.  When 
it  is  required  to  raise  a  frame,  with  its  skins,  or  hides, 
the  windlass  is  moved  along  the  railway  or  floor  imme- 
diately above  the  frame,  and  a  rope  with  a  hook  at  the 
end  is  let  down  to  the  frame,  which  is  then  attached 
thereto.  The  frame  is  then  raised  up  by  means  of  the 
windlass,  until  the  skins  are  drawn  out  of  the  liquid,  and 
are  completely  exposed  to  the  atmosphere ;  in  which  po- 
sition it  is  suspended  by  a  hook  w,  firmly  fastened  to  the 
beam  u,  where  it  remains  until  the  manufacturer  thinks 
it  advisable  to  immerse  the  hides  or  skins  again. 

"  Having  raised  one  frame  up,  and  suspended  it  from 
the  hook  the  attendant  releases  the  rope  belonging  to 
the  windlass,  and  proceeds  along  the  floor  or  railway 
with  the  windlass  to  another  frame,  which  he  raises  and 
suspends  from  its  hook  iv,  in  the  same  way.  When  it  is 
required  to  lower  the  frames,  and  their  hides,  or  skins, 
mto  the  liquor,  this  must  be  done  by  means  of  the  wind- 
lass, in  exactly  the  same  manner." 


20 


CHAPTER  XIX. 


TURNBULL'S  PROCESS. 

The  immediate  and  direct  combination  of  tannin  with 
the  gehitinous  tissue  of  skins,  is  retarded,  or  prevented, 
during  the  operation  of  tanning,  by  the  following  cir- 
cumstances. 

1st.  The  skins,  when  immersed  in  lime-water,  absorb 
a  considerable  quantity  of  lime,  which  has  the  effect  of 
rendering  soluble  and  removing  a  portion  of  gelatine,  or 
of  so  altering  the  nature  of  part  of  the  structure  as  to 
render  it  incapable  of  combining  properly  with  tannin ; 
and  so  much  of  the  lime  is  retained  in  the  skins,  that  the 
tanner  is  prevented  from  acting  upon  them  with  perfect 
freedom. 

2d.  When  catechu  is  employed  for  tanning,  the  leather 
made  by  it  is  very  permeable  to  water,  is  loose  and 
spongy  in  structure,  and  of  a  dark-red  color.  This  con- 
dition is  produced  by  the  catechuic  acid  and  extractive 
matters. 

3d.  When  oak-bark  and  other  substances  used  in  tan- 
ning, particularly  divi-divi  and  sumach,  are  macerated  in 
water,  exposure  to  the  atmosphere  causes  the  conversion 
of  part  of  their  tannin  into  gallic  acid,  which  is  a  sol- 
vent of  gelatine,  and  is  consequently  injurious  in  its 
action  upon  the  skins,  interfering  with  their  thorough 
conversion  into  leather,  and  rendering  the  latter  light, 
spongy,  and  inferior. 


tuenbull's  process. 


299 


The  chief  object  of  TurnbuH's  process  (patented  in 
England,  Sept.  6,  1844),  is  to  obviate  all  these  diffi- 
culties either  by  the  complete  removal  of  every  trace  of 
lime  from  the  skins,  or  by  obtaining  depilation  without 
the  aid  of  lime. 

Saccharine  substances  and  pyroxilic  or  wood  spirit 
possess  the  property  of  combining  with  and  dissolving 
lime ;  and  for  the  purpose  of  extracting  the  latter  from 
the  skins,  he  prepares  a  solution,  consisting  of  fourteen 
pounds  of  sawdust,  four  pounds  of  coarse  sugar  or  molas- 
ses, and  sixty  gallons  of  water ;  or  it  may  be  composed 
of  sawdust  alone,  in  the  proportion  of  twenty-eight  pounds 
to  the  same  quantity  of  water.  The  skins  are  soaked 
for  two  or  three  days  in  this  cold  solution,  which,  dur- 
ing that  interval,  dissolves  out  the  lime,  and  renders  the 
skins  more  capable  of  readily  absorbing  the  tanning 
material. 

For  the  purpose  of  depriving  the  skins  of  hair  without 
liming  them,  Turnbull  immerses  them  for  from  five  to  ten 
days,  first  in  a  solution  of  sugar,  which  swells  the  tissue, 
loosens  the  epidermis,  and  allows  the  ready  removal 
of  the  hair.  He  then  soaks  them  in  a  solution  of  sea- 
salt,  by  the  action  of  which  this  same  cuticle  is  made  to 
contract  and  separate  from  the  true  skin,  without  a 
corresponding  effect  being  produced  upon  the  gelatine. 
The  hair  can  then  be  easily  removed  without  the  least 
injury  to  the  gelatinous  structure.  The  saccharine  solu- 
tion is  composed  of  fourteen  pounds  of  coarse  sugar  to 
one  hundred  gallons  of  water,  and  is  maintained  at  a 
temperature  of  50°  to  80°  F.  The  other  solution  is 
formed  by  dissolving  fourteen  pounds  of  sea-salt  in  one 
hundred  gallons  of  water,  and  is  kept  at  a  temperature 
of  from  70°  to  100°  F. 

Turnbull  has  also  used  the  following  means  for  sepa- 


300 


turnbull's  process. 


rating  the  catechuic  acid  and  other  principles  injurious 
to  leather,  which  exist  in  catechu,  and  also  of  prevent- 
ing the  formation  of  gallic  and  ellagic  acids,  when  galls, 
oak-bark,  valonia,  and  divi-divi,  are  employed. 

For  separating  tannin  from  the  catechuic  acid,  the  cate- 
cliu  is  finely  powdered,  and  exhausted  of  soluble  matter,  by 
repeated  treatment  with  cold  or  milk-warm  water.  When 
the  solution  has  cooled,  it  is  to  be  strained  through 
cotton :  the  catechuic  acid  and  other  substances  injuri- 
ous to  leather  being  insoluble  in  cold  water,  are  retained 
upon  the  filter.  The  liquid  which  passes  through,  being 
a  solution  of  tannin  nearly  free  from  these  principles,  is 
much  better  adapted  for  preserving  the  sails  of  vessels, 
and  tissues  which  are  exposed  to  atmospheric  influences, 
than  an  ordinary  decoction  of  catechu.  In  order  to  pre- 
vent the  conversion  of  the  tannin  of  oak-bark  and  simi- 
lar tanning  substances  into  gallic  acid,  Turnbull  reduces 
the  materials  to  powder,  and  effects  the  tanning  without 
exposure  to  air,  as  hereafter  directed. 

The  skins  are  tanned  in  Turnbull's  process:  1st,  by  the 
application  of  a  force  difierent  from  hydrostatic  pressure 
or  capillary  attraction ;  2d,  by  the  employment  of  vats 
communicating  with  one  another  in  such  a  way  as  to 
maintain  a  constant  circulation  of  the  tanning  matter. 

The  first  means  consist  in  the  application  to  tanning, 
of  a  principle  similar  to  that  which  is  exhibited  in  the 
phenomena  of  endosmosis  and  exosmosis,  or  the  simultane- 
ous passage  in  opposite  directions  through  animal  mem- 
branes, of  fluids  of  different  densities.    For  this  purpose, 

the  hide  or  skin  to  be  tanned  is  formed  into  a  bag  by 
sewing,  and  the  oak-bark,  which  has  been  ground  into 
powder,  is  introduced,  in  the  proportion  of  two  pounds 
to  every  pound  weight  of  the  wet  skin,  prepared  as 
above;  the  opening  through  which  the  oak-bark  has 


turnbull's  process. 


301 


been  introduced  is  then  sewn  up,  leaving  only  a  small 
neck  or  aperture,  through  which  the  bag  is  filled  with 
cold  or  warm  water ;  and,  when  full,  the  neck  or  aper- 
ture is  fastened  by  a  flange  and  screw,  so  as  to  exclude 
the  atmospheric  air.  The  bag  is  then  introduced  into  a 
box  filled  with  tanning  liquor,  formed  of  terra-japonica, 
which  has  been  freed  as  above  described,  from  catechuic 
acid  and  extractives.  The  boxes  are  arranged  in  the 
manner  shown  at  Fig.  106,  A,  being  the  tanks,  or  boxes; 

Fig.  106. 


1^ 

H 

and  B,  the  waste-pipes  for  carrying  off  the  liquor,  as  it 
exudes  from  the  hides,  into  the  main  pipe  c,  leading  to 
the  main  tank  or  reservoir  d.  The  purified  terra-japonica 
is  not  injuriously  acted  upon  by  the  atmosphere  ;  and 
the  tanning  liquor,  composed  of  oak-bark,  being  mixed  in- 
side the  hide,  or  skin,  and  thus  excluded  from  the  action 
of  the  atmosphere,  does  not  generate  gallic  acid.  In 
order  to  increase  the  specific  gravity  of  the  liquor  in  the 
boxes,  or  tanks,  and  thus  accelerate  the  action,  sugar  is 
added  in  the  proportion  of  fourteen  pounds  to  one  hun- 
dred gallons  of  the  mixture  of  terra-japonica.  The  two 
liquids,  being  thus  separated,  the  process  of  endosmosis 
and  exosmosis  is  secured,  and  the  tannic  acid  passes 
rapidly  through  the  skin,  or  hide,  until  it  is  perfectly 
tanned  ;  the  bags  are  turned  occasionally,  and  when  they 
become  partially  empty,  by  exudation^  are  filled  again 


302 


turnbull's  process. 


with  water.  During  the  operation  of  tanning,  it  will  be 
necessary  to  add  to  the  weight  of  the  liquor  in  the  boxes, 
in  order  to  keep  up  the  action ;  this  is  accomplished  by 
adding  a  small  quantity  of  sugar  to  the  mixture  of 
terra-japonica.  Valonia  will  rank  next  to  purified  tan- 
nic acid  from  terra-japonica,  and  may  be  used  similarly 
to  terra-japonica;  ground  valonia  maybe  introduced  into 
the  bag,  in  the  proportion  of  about  one-half  less  than  the 
oak-bark  ;  divi-divi,  sumach,  and  other  substances  con- 
taining tannic  acid  may  be  used  in  the  same  proportions 
as  valonia.  Terra-japonica  ought  to  be  introduced  into 
the  bag,  after  the  impurities  are  removed,  in  the  form  of 
tan  liquor,  in  the  proportion  of  fifty  pounds  to  the  hide  : 
one  pound  of  terra-japonica  is  equal  to  four  pounds  of 
oak-bark. 

Fig.  107  represents  the  pits  or  tanks  for  tanning. 

Fig.  107. 


arranged  so  as  to  create  and  keep  up  a  general  and  con- 
stant agitation  and  circulation  of  the  tanning  liquor. 
Into  these  pits  or  tanks  is  introduced  a  sufficient  quan- 
tity of  tanning  liquor,  composed  either  of  terra-japonica, 
or  oak-bark,  divi-divi,  valonia,  sumach,  &c.,  so  as  to  leave 
room  only  for  the  hides  and  skins  which  are  placed 
therein,  one  upon  another,  as  in  the  ordinary  mode  of 
tanning ;  and  the  pits  are  then  closed  at  top,  so  as  to 
exclude  the  atmospheric  air.  The  tanning  liquor  must 
then  be  put  into,  and  kept  in  a  state  of  constant  agitation 
or  circulation;  this  is  effected  by  means  of  a  suction- 


turnbull's  process. 


303 


pump,  connected  with  the  pits  at  the  bottom  and  top.  A  is 
the  suction-pump ;  b,  b,  the  pits ;  C,  suction-pipe ;  D, 
pipes  leading  from  the  bottom  of  the  pits  to  the  suction- 
pipe  ;  E,  main  forcing-pipe,  connected  with  the  top  of  the 
pits  by  the  pipes  f,  f  ;  and  G,  G  are  pipes  which  connect 
the  pits  with  each  other  at  top,  to  prevent  them  from 
overflowing.  By  the  action  of  the  suction  or  forcing- 
pump,  the  tanning  liquor  is  speedily  extracted  from  the 
pits,  through  the  pipes  d,  d,  and  C,  and,  at  the  same  time, 
is  forced  again  through  the  pipes  e,  and  f,  f,  into  the  dif- 
ferent pits ;  thereby  keeping  up  a  general  agitation  and 
circulation  of  the  liquor.  These  pits  or  tanks  may  be 
constructed  in  sheds,  or  rooms,  and  placed  one  above 
another,  and  side  by  side  ;  but  if  it  is  desired  to  sink  the 
pits  in  the  earth,  they  should  be  constructed  and  arranged 
as  shown  at  Fig.  108,  in  which  the  same  letters  are  used 


to  denote  similar  parts  to  those  in  Fig.  107.  The  opera- 
tion of  both  arrangements  is  the  same,  with  this  excep- 
tion, that,  as  in  Fig.  108,  the  pits  are  sunk  in  the  ground, 
the  pipes,  by  which  the  liquor  is  withdrawn,  are  obliged 
to  enter  at  the  top,  and  descend  nearly  to  the  bottom  of 
the  pits. 

"  In  treating  terra-japonica,  for  the  purpose  of  sepa- 
rating the  tannic  acid  from  the  catechuic  acid  and  other 
extractive  and  deleterious  matter,  the  deposit,  remain ing 
in  the  cylinder  or  tank  is  at  least  fifty  per  cent,  of  the 


Fig.  108. 


304 


warington's  peocess. 


quantity  of  terra-japonic  a  dissolved  ;  and  it  is  capable  of 
being  purified,  and  rendered  applicable  to  tanning.  For 
this  purpose  it  is  placed  in  stoves  or  drying  pans,  heated 
to  160°  F.J  and  is  exposed  to  the  atmospheric  air,  and 
kept  continually  stirred,  until  it  assumes  the  color  and 
appearance  of  the  original  pulverized  terra-japonica;  this 
material  being  now  filtered,  will  be  found  to  yield  nearly 
as  much  tannic  acid  as  the  terra-japonica  did  in  the  first 
instance. 

Hides  and  skins  from  which  the  lime  has  been  ex- 
tracted, or  from  which  the  hair  has  been  removed  without 
the  use  of  lime,  by  the  above  modes  described,  may  be 
tanned  in  the  ordinary  manner,  by  terra-japonica,  puri- 
fied as  above,  and  by  other  ordinary  tanning  matter, 
with  much  greater  facility  than  heretofore  ;  and  leather 
of  greater  weight,  and  better  quality  than  usual,  will  be 
produced." 

warington's  process. 

This  is  an  English  method,  patented  March  16,  1841, 
by  Robert  Warington,  and  is  said  by  the  inventor  to  be 
applicable  to  the  tanning  of  all  kinds  of  hides  and  skins, 
Avhether  dry,  salted,  or  fresh. 

"  First,  for  soaking  or  preparing  the  hides  or  skins  for 
unhairing.  This  I  do  by  means  of  the  carbonates  of 
potass  or  soda;  the  latter,  from  its  cheapness,  is  to  be 
preferred,  and  dissolved  in  water,  in  the  proportion  of 
from  one  to  two  pounds  of  the  carbonate  to  ten  gallons 
of  water. 

"  Second,  for  the  preparing  the  hides  and  skins  for  un- 
hairing, and  swelling  them  at  the  same  time,  or  for 
swelling  them  only;  and  this  I  do  by  various  agents, 
which,  for  simplicity  of  explanation,  I  will  divide  into 


warington's  process. 


305 


three  classes :  first,  baryta,  potassa,  soda;  second,  muriatic 
acid,  nitric  acid,  and  oxalic  acid,  and  all  other  acids  (ex- 
cept the  sulphuric) ;  and  thirdly,  vegetable  matters,  as 
the  culinary  rhubarbs,  sorrel,  apple  marc,  vine  cuttings, 
and  many  others,  which,  from  locality  and  other  circum- 
stances, may  be  economically  employed.  Of  the  first 
class,  I  prefer  the  use  of  soda,  in  the  proportion  of  half  a 
pound  to  one  pound  of  dry  carbonate  of  soda  to  ten  gal- 
lons of  water,  and  rendered  caustic  by  about  half  its 
weight  of  fresh-burnt  lime.  Of  the  second  class,  I  prefer, 
from  its  cheapness,  the  muriatic  acid,  which  I  use  in  the 
proportion  of  from  half  a  pound  to  two  pounds  of  the 
acid  of  commerce,  of  specific  gravity  1.17,  mixed  with 
ten  gallons  of  water.  Of  the  third  class,  I  prefer  the 
culinary  rhubarbs,  bruised  and  mixed  with  water,  in  the 
proportion  of  from  one  to  ten  pounds  of  the  rhubarb  per 
gallon  of  water.  As  the  details  of  the  method  of  un- 
hairing  and  fleshing  the  hides  or  skins  when  ready,  is 
the  same  exactly  as  that  usually  followed,  and  is  well 
known  to  all  practical  men,  it  would  be  useless  to  state 
them  here. 

"  Third,  for  the  use  of  the  carbonates  of  ammonia  in 
the  operation  of  graining,  and  this  I  employ  in  the  pro- 
portion of  from  half  a  pound  to  four  pounds  dissolved  in 
ten  gallons  of  water. 

"  Fourth,  for  the  use  of  green  vegetable  matter  bruised 
— as  culinary  rhubarb,  bruised  potatoes,  &c. — or  chemi- 
cal agents,  capable  of  deoxidizing  or  preventing  oxida- 
tion— as  gum,  starch,  certain  compounds  of  sulphur,  &c., 
which  are  to  be  mixed  in  small  proportions  with  the 
tanning  material — as  barks,  divi-divi — or  extracts — as 
kino,  catechu,  &c.  The  proportion  in  which  these  agents 
may  be  employed  are  so  various,  and  dependent  on  the 
tanning  agent  used,  that  it  is  impossible  to  give  an  accu- 


306 


warington's  process. 


rate  proportion,  but  from  one-hundredth  part  to  one-tenth, 
supposing  oak-bark  to  be  employed. 

"  Fifth,  for  the  use  of  bichromate  of  potass  in  solution, 
or  diluted  sulphuric  acid,  for  the  preservation  of  animal 
matter,  so  as  to  prevent  putrefaction.  When  the  bi- 
chromate of  potass  is  used,  I  employ  from  one-eighth  to 
half  a  pound  to  100  gallons  of  water;  and,  in  the  case  of 
sulphuric  acid,  from  one-fourth  to  one  pound  to  ten  gal- 
lons of  water.  Into  either  of  these  solutions,  the  skins, 
or  any  other  animal  substances,  in  their  moist  state,  are 
to  be  immersed  and  kept  from  the  dust.  I  do  not  claim 
the  use  of  any  of  the  proportions  hereinbefore  given,  as 
these  must  be  regulated  by  the  nature  of  the  material 
operated  upon,  and  the  temperature  of  the  air  and  season 
when  it  is  employed." 


CHAPTER  XX. 

H.  HIBBARD'S  PATENT  PROCESS. 

This  process,  patented  in  October,  1849,  is  said  to 
possess,  in  an  eminent  degree,  the  advantages  of  economy 
of  time  and  material.  It  is  also  applicable  to  the  tan- 
ning of  all  kinds  of  skins,  and  produces  leather  of  great 
strength  and  durability. 

The  inventor  describes  his  process  as  consisting : — 
^'  First.  In  the  use  of  a  composition  of  lime,  wood  ashes 
(or  potash),  and  salt,  for  the  purpose  of  removing  hair 
or  wool;  also  for  the  purpose  of  timing.'  so  called,  instead 
of  using  lime  alone,  as  in  the  old  method.  Lime  and 
ashes  have  been  used  separately  for  the  purpose  of  re- 
moving hair,  wool,  grease,  mucus,  and  other  impurities 
from  skins;  but  lime  alone  requires  several  days,  and,  in 
cold  weather,  weeks,  to  effect  these  several  objects;  so 
that  the  muscular  fibre  of  the  skin  is  always  more  or 
less  injured.  On  the  other  hand,  ash^s  alone  acts  too 
rapidly,  and  would  destroy  the  skins  altogether;  but 
when  lime,  ashes,  and  salt  are  combined  in  proper  pro- 
portions, the  salt  modifies  the  action  of  the  alkalies,  and 
protects  the  skins  from  their  caustic  properties;  so  that 
the  processes  of  unhairing  and  timing'  are  both  rendered 
more  expeditious  and  safe  than  by  the  old  method.  The 
texture  of  the  skin  is  uninjured,  and,  consequently,  the 
leather  is  much  stronger. 


308 


hibbard's  patent  process. 


Second.  In  the  use  of  a  composition  of  salt,  sulphuric 
acid  (oil  of  vitriol),  and  sumach,  oak,  hemlock  bark,  or 
any  other  tannin  for  the  process  of  tanning.  The  salt, 
sulphuric  acid,  and  tannin  being  mixed  together  in  water, 
in  certain  proportions  hereafter  mentioned,  a  portion  of 
the  salt  is  decomposed  by  the  acid,  forming  sulphate  of 
soda,  and  setting  muriatic  acid  free,  which  [the  muriatic 
acid),  being  absorbed  by  the  water,  acts  directly  and 
rapidly  on  the  skins,  opening  their  pores,  and  preparing 
them  for  the  tannin,  which,  being  present  also  in  the 
mixture,  immediately  and  readily  unites  with  the  gela- 
tine of  the  skins,  forming  leather  more  expeditiously  and 
perfectly  than  by  the  old  method  of  tanning."  * 


PREPARATION  OF  THE  SKINS. 

"The  skins  may  be  prepared  for  the  tanning  process 
after  the  usual  method.  But  I  prefer  and  use  the  fol- 
lowing composition,  which  I  shall  denominate — 

Composition,  No.  1. 

Quicklime,  fresh  slacked        .       .    i  bushel 
Good  wood  ashes    .       .       .       .    i  " 
Chloride  of  sodium  (salt)         .       .    3  pints. 
"  N.  B. — For  the  ashes  may  be  substituted  three  to 
five  pounds  of  potash. 

"For  removing  the  hair  or  wool,  the  above  comjDosi- 
tion,  No.  1,  is  to  be  mixed  with  water  sufficient  to  make 
a  thick  paste,  and  applied  to  the  flesh  side  of  the  hides 
in  the  usual  way;  the  skins  to  be  folded  and  kept  at  a 
temperature  of  summer  heat.  In  a  few  hours  they  will 
be  ready  to  pull. 

"For  the  liming  (or  ashing)  process,  I  use  the  same 


4 


hibbard's  patent  process.  309 

composition  J  No.  1,  mixed  with  a  sufficiency  of  water  in 
.  a  vat,  to  immerse  the  number  of  skins  proposed  to  be 
limed  (ashed).  One  bushel  of  the  mixture  is  about 
equivalent  to  one  bushel  of  lime  alone.  The  liming  (or 
ashing)  process  may  be  conducted  at  a  temperature  of 
40°  to  60°  F." 

COMPOSITION  FOR  TANNING. 

"  For  six  dozen  of  full-sized  sheep,  deer,  goat,  or  simi- 
lar skins  of  similar  size. 


Comjposition,  No,  2. 

Chloride  of  sodium  (salt)        .       .  18  lbs. 

Sulphuric  acid        .       .       .       .  2  " 

Sicily  sumach,  or  quercitron  bark    .  36  " 

Muriatic  acid         .       .       .       .  2  oz. 

Dried  clover   18  lbs. 

Soft  water   125  galls." 


The  sumach  or  dye-stuffs  are  first  exhausted  wdth  water, 
and  then  the  salt  is  added  to  the  liquor,  apportioned  so  as 
to  insure  perfect  solution.  Subsequently,  the  acids  are 
added,  and  the  mixture  thoroughly  incorporated  by 
stirring. 

The  details  of  this  process  and  the  modifications  ne- 
cessary to  make  it  applicable  to  the  tanning  of  morocco, 
white,  glove,  and  harness  leathers,  are  given  in  a  short 
treatise  upon  the  subject  by  Dr.  W.  W.  Reid,  of  Roches- 
ter, New  York.  Being  a  copy-right  publication,  we  are 
not  at  liberty  to  extract  or  condense  from  it,  and  the 
reader  must  apply  to  the  original  source,  if  he  should 
desire  further  information. 


CHAPTER  XXI. 


LEPEIEUR'S  PROCESS. 

This  process,  published  in  1833,  consists  of  four 
operations,  which,  with  some  modifications,  are  those 
practised  by  all  tanners. 

1.  The  rinsing,  or  dressing  in  water,  which  compre- 
hends the  softening  of  dry  skins,  the  washing,  the 
separation  of  the  hair,  the  fleshing,  &c. 

2.  The  sugar  of  lead  hath. — The  skins,  having  been 
well  washed  and  drained,  are  deposited  and  left  during 
ten  or  twelve  hours  in  summer,  and  from  twenty-four  to 
thirty  hours  in  winter,  in  a  bath  containing  one  pound 
one  and  a  half  ounces  of  acetate  of  lead  for  every  six  or 
eight  skins,  being  in  the  proportion  of  one  part  of  the 
salt  to  1000  parts  of  water.  The  skins  are  then  taken 
out  and  are  again  placed  in  a  similar  bath,  in  which  they 
are  allowed  to  remain  for  from  twelve  to  twenty-four 
hours,  care  being  taken  to  handle  them  every  three 
hours  during  each  immersion.  They  are  then  carefully 
rinsed  in  running  water.  The  author  believes  that  the 
combination  of  the  lead  salt  with  the  albumen  of  the 
skins  gives  them  a  solidity,  and  freedom  from  looseness 
of  texture  which  they  would  not  otherwise  possess. 

3.  Tan-liquor  haths. — The  author,  after  contending  that 
the  raising  of  skins  is  not  essential,  and  that,  if  consi- 
dered necessary,  it  can  readily  be  effected  by  adding  acid 


leprieur's  process. 


311 


to  the  first  infusions,  gives  the  proportions  of  one  part  of 
tan  for  ten  parts  of  dry  hides,  with  enough  sulphuric 
acid  to  impart  a  distinct  acid  taste,  as  being  all-sufiicient 
for  the  purpose. 

First  Series  of  Tan  Infusions.  First  hath, — This  is 
composed  of  22  pounds  of  tan  for  every  110  pounds  of 
hides,  infused  for  twenty-four  hours  in  enough  water  to 
cover  but  not  to  completely  sink  them.  To  this  mix- 
ture, a  quantity  of  strong  sour  ooze,  or  else  from  9  i  to  91 
ounces,  by  weight,  of  sulphuric  acid,  at  66°  B.,  are  added, 
and  if,  after  maceration  for  twenty-four  hours,  the  liquid 
is  not  sensibly  acid,  more  is  poured  in,  if  it  is  desired  to 
effect  the  raising  by  means  of  it. 

In  summer,  the  hides  should  not  be  kept  in  this  bath 
more  than  thirty  or  forty  hours,  since,  at  the  end  of  that 
time,  it  is  exhausted,  and  disposed  to  putrefy,  from  the 
quantity  of  animal  matter  then  contained  in  it.  In 
winter,  this  tendency  being  retarded,  they  may  remain 
in  it  a  day  longer. 

Second  hath. — 33  pounds  of  tan  for  110  pounds  of  dry 
leather  are  deposited  in  this  bath,  which  is  to  be  acidified 
in  the  same  way  as  the  first.  The  skins  should  be  kept 
in  it  for  thirty-six  hours,  after  which  time  they  are  taken 
out  to  drain,  reimmersed  for  thirty  hours  more,  and  again 
drained.  On  account  of  the  animal  matter  contained  in 
the  infusion,  it  is  now  no  longer  serviceable  except  as  a 
putrid  ferment  for  new  infusions. 

Third  hath. — In  this  bath,  44  pounds  of  tan  are  used 
for  the  above-mentioned  weight  of  skins,  and  not  more 
than  9i  ounces  of  sulphuric  acid  are  added,  if  the  pre- 
vious raising  has  been  considered  sulBicient.  The  skins 
should  be  taken  out  at  intervals,  as  in  the  former  opera- 
tions, washed  in  water,  drained,  and  replaced.  The 
author  remarks  that  if,  after  a  continuance  in  the  bath 


312 


leprieur's  process. 


of  four  or  five  days,  it  shows  3°  or  4°  by  the  acid  hydro- 
meter, the  skins  may  be  allowed  to  remain  twenty-four 
hours  longer;  or,  still  better,  the  liquid  may  be  used,  in 
the  same  manner  as  the  first  bath,  for  thin  skins,  like 
those  of  the  calf,  goat,  sheep,  &c. 

Fourth  hath. — 55  pounds  of  tan,  the  same  mode  of  pre- 
paration (excepting  the  use  of  less  water),  the  same 
acidification,  and  a  continuance  of  the  skins  in  it  for  six 
or  eight  days,  are  required  in  this  fourth  process.  The 
skins,  before  being  placed  in  the  vat,  are  drained  for 
eight  or  twelve  hours,  and  afterwards  are  taken  out  at 
least  three  times,  so  that  it  may  be  ascertained  that  the 
liquor  has  not  become  too  weak.  If  the  degree  shown 
by  the  acid  hydrometer  is  four  or  five  tenths,  a  fresh 
liquid  is  prepared,  and  the  old  one  is  reserved  for  skins 
which  are  undergoing  the  second  series  of  baths.  The 
author  adds  that  it  is  better  generally  to  deposit  fresh 
skins  in  old  baths,  which  they  quickly  exhaust,  than  in 
those  more  advanced. 

Second  Series  of  Infusions.  First  hath. — Accord- 
ing to  Leprieur,  a  new  set  of  skins  begins  with  the  fourth 
bath  of  the  first  series  of  infusions,  and  will  require  330 
lbs.  of  bark,  to  tan  them  as  completely  as  the  others. 

Second  hath. — Since  the  fifth  bath  of  the  first  series 
would  not  be  disposed  of  in  time  to  answer  for  the  se- 
cond bath  of  the  second  series,  and  would,  moreover,  be 
too  strong,  a  new  one  should  be  prepared  like  that  of 
Number  2. 

Leprieur  recommends  after  the  fourth  bath,  to  stratify 
the  leather  and  tan  alternately,  interposing  peeled  willow 
twigs  or  strips  of  white  wood,  so  that  the  surfaces  shall 
be  equally  soaked. 

First  Series.  Fifth  hath.—m  lbs.  of  tan  for  110  of 
hides.    The  latter  kept  in  the  vat  for  from  six  to  eight 


leprieur's  process. 


313 


days,  should  be  taken  out,  drained,  and  replaced  three  or 
four  times  during  this  period.  If  strips  are  placed  be- 
tween them,  it  will  be  sufficient  to  cover  the  last  layer 
of  tan  with  the  infusion,  to  the  height  of  half  an  inch. 

Second  Series.  Third  hath. — The  fifth  bath  forms 
the  third  of  the  second  series. 

Sixth  hath, — Consists  of  66  lbs.  of  tan  to  110  lbs.  of 
hides,  which  remain  in  it  about  ten  days,  and  are  taken 
out  and  drained  at  intervals  of  two  or  three  days.  It  is 
well  to  observe  that  when  the  infusion  marks  more  than 
five  or  six  of  the  acid  hydrometer,  the  skins  should  be 
taken  out,  and  the  bath  reserved  for  others  which  are 
less  advanced  in  preparation. 

Fourth  hath, — The  sixth  bath,  like  the  fifth,  not  being 
unoccupied  soon  enough  to  answer  for  the  fourth  of  the 
second  series,  it  is  necessary  to  prepare  it  with  fresh 
materials,  like  No.  4,  It  will  then  be  the  sixth  of  the 
first  series  under  the  denomination  five. 

Fifth  hath, — There  being  no  further  danger  of  putre- 
faction to  the  hides,  they  can  now  remain  in  this  bath 
until  the  fifth  bath  of  the  first  series  is  fully  prepared. 

Seventh  hath, — Consists  of  bark  88  lbs.  for  110  lbs.  of 
hides,  which  should  remain  in  it  for  twelve  or  fifteen 
days,  or  until  the  liquid  marks  no  more  than  from  six 
to  seven  tenths  by  the  hydrometer.  After  that  time  it 
will  serve  for  the  second  set  of  skins.  When  the  hides 
are  taken  from  this  bath  and  cut,  the  sections  will  show 
a  well-tanned  surface,  but  an  unchanged  interior. 

Nearly  fifty  days  will  now  have  elapsed  since  the 
skins  were  placed  in  the  first  bath,  and  for  every  110 
lbs.  of  hides,  385  lbs.  of  bark  will  have  been  consumed. 
Supposing  now  that  1100  lbs.  of  tan  are  used  in  the 
ordinary  method  of  tanning  that  weight  of  leather,  there 
21 


314 


leprieur's  process. 


will  still  remain  717  lbs.  to  be  used  in  the  pits,  to  make 
the  expenditure  of  material  the  same  in  both  processes. 

Sixth  hath. — The  seventh  bath  of  the  first  series  is 
the  sixth  of  the  second;  but  the  author  regards  it  as  a 
matter  of  indifference,  whether  the  hides  are  at  once 
deposited  in  the  vats,  or  are  again  exposed  to  a  bath  of 
110  lbs.  of  tan  to  an  equal  weight  of  leather. 

TANNING  IN  THE  VATS. 

Leprieur  uses  tan  well  mixed  with  water,  to  which 
sulphuric  acid  has  been  added  in  the  proportions  before 
mentioned,  so  as  to  saturate  the  potassa  of  the  bark.  A 
layer  of  this  mixture  is  deposited  upon  the  bottom  of 
the  vat,  a  hide  is  spread  out  upon  it,  and  the  stratifica- 
tion is  continued  in  this  way  until  the  vat  is  filled.  This 
last  hide  is  covered  with  a  stratum  of  one  inch  of  the 
mixture;  a  sufiicient  quantity  of  water  to  rise  above  the 
surface  is  then  thrown  in,  and  weighted  planks  are  placed 
over  the  whole,  to  prevent  the  skins  from  floating. 
After  the  commencement  of  the  process,  the  liquid  in 
the  vat  should  be  tested  every  three  or  four  days  with 
the  hydrometer,  so  as  to  ascertain  if  any  diminution 
of  strength  has  taken  place.  In  that  event  the  skins 
should  be  taken  out  and  deposited  in  another  vat.  For 
the  purpose  of  being  more  explicit  in  regard  to  the 
determination  of  the  density  of  the  infusion,  Leprieur 
adds:  Taking  into  consideration  the  fact  that  110  lbs. 
of  good  tan,  furnish  1320  lbs.  of  infusion,  marking  one 
degree  of  the  strong  hydrometers,  and  ten  or  twelve 
tenths  of  the  acid  hydrometers  after  forty-eight  hours, 
it  will  be  easy  to  ascertain  day  by  day  from  the  diminu- 
tion in  density  of  the  liquid,  how  much  of  the  tanning 
principle  has  been  absorbed  by  the  skins.    When  the 


leprieur's  process. 


315 


infusion  is  thus  diminished  in  strength  by  one-half,  it 
will  still  serve  for  other  processes,  and  another  supply  of 
tan  can  be  given." 

We  abstain  from  referring  to  the  accessory  circum- 
stances which  will  more  or  less  affect  this  absorption,  our 
intention  being  only,  as  throughout  this  account,  to  make 
known  the  details  of  the  author's  process,  as  given  by 
himself. 

First  Tanning  in  Yat. — 100  parts  of  tan  for  every 
100  parts  of  hides,  are  used  in  the  first  vat,  the  water 
being  mixed  as  before,  with  rather  more  than  nine  ounces 
by  weight  of  sulphuric  acid.  The  skins  are  to  be  re- 
tained in  this  first  vat  from  twelve  to  fifteen  days;  and 
besides  the  testing  of  the  liquor  by  the  hydrometer,  they 
should  be  cut  from  time  to  time,  so  as  to  ascertain  what 
progress  the  tanning  has  made.  If  considerably  ad- 
vanced, and  if  the  liquid  is  reduced  to  five  or  six  tenths, 
the  vat  should  be  changed. 

Second  Series. — The  contents  of  the  first  vat  are  not 
exhausted,  but  furnish  a  strong  infusion  for  a  sixth  bath 
for  the  second  set  of  skins. 

Second  Tanning  in  the  Yat. — Consists  of  exposure 
of  100  parts  of  skins,  with  120  of  tan,  prepared  like  the 
preceding,  for  about  fifteen  days. 

First  Tanning  in  Vat. — The  preceding,  or  second  tan- 
ning of  the  first  series,  forms  the  first  tanning  of  the  se- 
cond series.  The  skins  taken  from  the  first  tanning  are 
then  exposed  to  the  second. 

Third  Tanning  in  Vat. — Consists  of  exposing  100 
parts  of  hides,  with  130  of  bark,  for  from  fifteen  to 
twenty  days,  the  preparation  being  the  same  as  before. 
The  hides  taken  from  this  vat  should  be  carefully  exam- 
ined, as  the  thinnest  ones  are  probably  tanned. 

Fourth  Tanning. — This  is  the  second  of  the  second 


316 


leprieur's  process. 


series.  140  parts  of  tan,  for  100  of  hides  are  used  for 
from  fifteen  to  twenty  days,  the  preparation  being  the 
same  as  before. 

Third  Tanning. — The  preceding,  or  the  fourth  of  the 
first  series,  serves  as  the  third  for  the  second  series. 

Fifth  Tanning. — In  this  100  parts  of  hides  are  ex- 
posed to  160  parts  of  tan,  for  from  twenty  to  thirty  days, 
this  quantity  of  176  lbs.  completing  the  1100  lbs.  used 
for  the  first  series.  This  last  tanning  is  seldom  con- 
sidered necessary  for  good  skins,  or  where  the  bark  is  of 
good  quality. 

Fourth  Tanning. — This  is  the  fifth  for  the  first  series. 

If  at  the  end  of  twenty  days  the  tanning  is  not  found 
to  be  already  completed,  from  fifteen  to  twenty  days 
more  may  be  allowed  to  elapse  before  the  leather  is 
taken  out,  this  being  the  last  tanning  of  all. 

If  it  should  be  necessary  to  add  220  lbs.  more  of  tan 
to  the  amount  already  used,  220  lbs.  of  leather  would  be 
completely  tanned,  by  means  of  1650  lbs.  of  bark. 

In  order  not  to  lose  time  in  the  series  of  complicated 
operations  of  this  process,  the  fresh  baths  and  vats  should 
be  prepared  as  soon  as  the  operations  of  the  preceding 
ones  are  nearly  concluded. 

REVIEW  OP  THE  QUANTITIES  OF   TAN   EMPLOYED  IN  THE  PRECEDING 


PROCESSES  FOR  TANNING  220  POUNDS  OF  LEATHER. 


First  Series, 


Tan  for  baths 
Tan  for  pits 


385 
716 


Second  Series. 


Tan  for  baths 
Tan  for  pits 


88 
176 


264  lbs: 


1365  lbs. 


leprieur's  process. 


317 


According  to  Leprieur's  account,  strong  and  supple 
hides  are  tanned  by  his  process,  in  from  100  to  130  days, 
middling  ones  in  150  days,  and  refractory  ones  in  about 
180  days.  Sometimes  a  sixth  tanning  is  required,  which 
will  not  much  increase  the  duration  or  expense  of  their 
preparation. 


CHAPTER  XXII. 


TANNING  WITH  EXTRACT  OF  OAK-BAEK  OR  CATECHU. 

Burhridge's  Process, — Burbridge  regulates  the  strength 
of  the  extract  by  a  hydrometer,  especially  adapted  to 
the  purpose,  which  he  calls  a  harkometer.  He  commences 
the  process  with  a  weak  solution  at  3°  of  his  meter,  and 
gradually  increases  its  force,  changing  it  three  times  a 
week,  until  a  strength  of  15°  or  20°  is  arrived  at. 

In  the  old  method,  tanners  are  usually  satisfied  if  forty 
parts,  by  weight,  of  hides  in  the  raw  state  are  not  dimin- 
ished more  than  one-half  after  a  year  s  exposure  in  the 
vats.  But  an  equal  quantity,  tanned  by  Burbridge's  pro- 
cess, is  found  to  weigh  twenty-four  parts  after  three 
months,  which  has  convinced  him  that  the  longer  expo- 
sure is  detrimental  to  the  leather.  He  does  not  consume 
more  tan  than  is  used  in  the  slower  methods,  four  parts 
being  generally  sufficient  to  tan  one  of  skins. 

Burbridge  has  also  proposed  to  substitute  the  terra 
jajponica^  or  catechu^  for  oak-bark.  Mr.  J.  Dauks  reported, 
in  the  year  1812,  to  the  East  India  Company,  that 
catechu  contained  ten  times  as  much  tanning  matter  as 
oak-bark,  and  the  Company,  induced  by  his  representa- 
tions, made  every  effort  to  encourage  its  use;  but  all 
attempts,  by  them  and  by  government,  to  make  it  take 
the  place  of  the  substance  in  common  use  have  failed. 
It  certainly  could  be  procured  at  a  much  lower  price 


burbridge's  process. 


319 


than  the  equivalent  amount  of  oak-bark ;  therefore,  some 
practical  objection  to  its  use,  of  which  we  are  ignorant, 
must  have  prevented  its  adoption. 

John  Burbridge  proposes  to  reduce  the  time  of  tanning 
sole  leather  to  three  or  four  months,  by  the  use  of  oak- 
extract,  which  he  prepares  without  loss  in  ten  days. 


CHAPTER  XXIII. 


HEMLOCK  TANNING. 

The  hemlock  forests  of  New  York  and  northern  Penn- 
sylvania are  very  extensive,  and  the  readiness  and  cheap- 
ness with  which  the  bark  may  be  obtained  have  brought 
it  into  general  use,  in  those  States,  as  tanning  material. 
It  may  be  employed  alone,  or  in  combination  with  oak- 
bark.  The  Hon.  Zadock  Pratt,  who  is  the  most  skilful 
and  experienced  manufacturer  of  leather  in  the  United 
States,  has  kindly  furnished  me  with  the  following  par- 
ticulars of  his  tanneries  at  Prattsville,  N.  Y.,  wherein  it 
is  used  to  the  extent  of  6000  cords  annually.  His  state- 
ment is  so  full  and  comprehensive,  that  we  give  it  in 
the  original  language. 

"My  tannery  is  an  immense  wooden  building,  530  feet 
in  length,  43  feet  in  breadth,  and  two  stories  and  a  half 
high.  Adjoining  the  centre  of  the  tannery,  are  two  bark 
sheds,  125  feet  long  by  24  wide;  and,  near  the  east  end 
of  the  tannery,  a  store-house  40  by  60.  On  the  same 
level,  100  feet  from  the  tannery,  are  some  dozen  houses, 
built  in  a  line  parallel  with  the  tannery,  for  the  con- 
venience of  the  workmen.  The  main  road  through  the 
village  is  about  twelve  rods  distant,  and  parallel  with 
the  tannery.  Within  the  area  of  the  tannery  are  con- 
tained 300  vats,  tanning  over  60,000  sides  a  year,  with 
conductors  to  draw  the  liquor  to  the  pump,  affording 


HEMLOCK  TANNING. 


321 


about  46,000  cubic  feet  of  room  for  tanning  purposes^ 
and  7640  in  the  beam-house.  A  large  wing,  40  by  80 
feet,  extending  over  the  stream,  contains  twelve  leaches, 
six  of  them  furnished  with  copper  heaters,  containing 
about  13,000  feet,  and  also  the  back  loft,  through  which, 
in  the  course  of  the  year,  passes  more  than  6000  cords 
of  bark.  The  mills  through  which  it  is  ground  are  capa- 
ble of  grinding  over  a  cord  of  bark  per  hour;  and  it  has 
connected  with  it  a  pump  of  sufficient  capacity  to  deliver 
1000  feet  of  ^ooze,'  or  water  charged  with  tannin,  in  30 
minutes.  The  beam-house  contains  30  vats,  equivalent 
to  7640  cubic  feet.  It  has  connected  with  it  three  hide- 
mills,*  for  softening  the  dry  Spanish  hides,  and  two  roll- 

*  Hide-Mills,  or  Fulling-Stocks. — These  macliines  are  employed 
for  softening  the  hides,  and  thus,  by  bringing  them  as  nearly  as  possible 
to  the  fresh  state,  to  facilitate  the  after  processes  of  depilation  and  tanning. 

Monier  and  Ray^s  Mill. — Skins  with  the  hair  on  are  first  soaked  in 
cold  water  for  forty-eight  hours,  and  are  then  subjected  to  the  action  of 
the  machine  for  an  hour  and  a  half;  exposure  for  which  time  is  generally 
sufficient  to  render  them  pliable.  Eight  or  ten  skins,  according  to  their 
size  and  thickness,  are  generally  contained  in  the  apparatus.  The  water 
is  then  allowed  to  drain  off,  a  sufficient  quantity  of  cream  of  lime  is 
poured  in,  and  the  skins  are  beaten  again  for  four  hours,  when  they  are 
taken  out  and  piled  up.  After  haying  been  left  to  drain  for  five  hours 
in  this  position,  they  are  again  fulled  for  a  time  in  the  machine,  and  then 
are  deprived  of  their  hair  and  fleshed  by  the  workmen.  They  are  then 
beaten  for  an  hour  and  a  half  in  the  machine,  and  cleaned  and  scraped 
with  the  slate.  In  order  to  remove  the  lime,  some  of  which  still  re- 
mains attached  to  the  skins,  they  are  now  soaked  in  water  containing 
one-hundredth  part  of  sulphuric  acid,  and,  after  being  constantly  stirred 
about  in  this  liquid  for  an  hour,  are  washed  and  rinsed  in  running  water. 

This  method  of  preparing  skins  for  tanning,  dispenses  with  the  laborious 
manipulations  to  which  they  are  commonly  subjected,  and  preserves  their 
quality,  not  injured  as  they  are  in  the  old  way,  by  the  hands  of  the 
workmen.  It  also  presents  the  additional  advantage,  that  they  do  not 
require  the  long  exposure  to  the  action  of  lime,  which  is  so  apt  to  injure 
their  tissue. 


322 


HEMLOCK  TANNING. 


ing  machines,  capable  of  rolling  500  sides  of  leather  per 
day.    Outside  of  the  building,  but  connected  with  the 

Description  of  this  machine,  as  it  has  been  improved^  enlarged,  and 
prepared  for  the  fulling  ofhoth  small  and  large  skins. 
Fig.  109.  Side  elevation. 
Fig.  110.  Front  view. 
Fig.  111.  Plan. 


Fig.  109. 


(a.)  Trough  in  wliich  the  skins  are  placed. 

(5.)  Upright  rising  above  the  trough,  and  supporting  the  levers  (c) 
near  its  upper  extremity,  where  they  are  attached  to  a  crosspiece  (d). 

(e.)  Wedge  pressing  upon  the  upright  (5),  and  giving  it  the  necessary 
inclination. 

(/.)  Mallets  or  hammers  attached  to  the  lower  end  of  the  levers  (c), 
and  acting  upon  the  skins  in  the  hollow  part  of  the  trough  (a),  formed 
by  the  curved  line  seen  at  {g). 

(h.)  Wedges  arranged  so  as  to  keep  the  mallets  inclined  in  the  proper 
direction  to  the  curve  (g)  of  the  trough. 

({.)  Other  wedges  serving  the  same  purpose. 

Qc).  Two  curved  uprights  rising  above  the  trough  and  preventing  the 
mallets  from  swaying. 


HEMLOCK  TANNING. 


beam-house  by  an  underground  communication,  are  eight 
stone  sweat-pits,  with  pointed  arches  and  flues.  The 

(J.)  Crosspiece  uniting  the  uprights  {k). 

(m.)  Vertical  wheel,  or  turnstile,  with  four  arms,  the  axis  (n)  of  which 
turns  in  the  uprights  (/j),  and  is  the  shaft  for  the  cords  (o)  which  keep 
the  mallets  suspended. 

Fig.  110. 


(p.)  Wheel  turned  by  a  stream  or  fall  of  water,  its  axle  (q)  carrying 
cams  (r),  which,  in  turning,  alternately  raise  and  lower  the  mallets  (/). 

Fig.  111. 

Ml 


324 


HEMLOCK  TANNING. 


pins  are  of  the  most  approved  size,  being  in  area  10  feet 
by  14,  and  in  depth  8  feet,  with  a  spring  of  water  at  one 
corner. 

There  are  some  recent  improvements^  in  Monier  and  Ray^s  process, 
which  refer  to  pressing  the  skins,  to  the  liquid  in  which  they  are  raised^ 
and  to  their  liming. 

Since  pure  water  is  a  solvent,  and  is  capable  of  injuring  the  quality  of 
the  leather,  if  left  for  too  long  a  time  in  contact  with  the  tissues  of  the 
skins,  it  is  evident  that,  if  the  latter  are  entirely  deprived  of  it  before 
being  placed  in  the  infusion  of  bark,  their  complete  tanning  will  be 
much  facilitated  and  hastened.  To  secure  this  desirable  result,  after 
having  been  perfectly  cleaned,  scraped,  and  rinsed,  they  are  to  be  sub- 
jected to  the  action  of  a  powerful  common  press,  which  deprives  them  of 
nearly  all  their  free  watery  contents.  After  this  compression,  they  are 
then  deposited  in  a  vat  containing  weak  tan  infusion,  are  left  in  it  for 
six  days,  are  taken  out  and  again  pressed,  and  then  deposited  in  a  vat 
containing  a  stronger  infusion,  which  is  kept  of  uniform  strength  for  a 
period  of  ten  days.    At  the  end  of  this  time  they  are  taken  out,  pressed 


Fig.  112. 


HEMLOCK  TANNING. 


325 


"  Since  I  first  commenced  business,  tlie  gain  of  weight 
in  converting  hides  into  leather,  has  been  increased  nearly 
50  per  cent.  That  is,  that  from  a  quarter  to  a  third 
more  leather  can  now  be  obtained  from  a  given  quantity 
of  hides,  than  at  the  time  when  I  learned  my  trade  at 
my  father's  tannery,  conducted  in  the  old-fashioned  way, 
some  40  years  ago. 

"  The  great  improvement  in  weight  seems  to  have  been 
gained  by  the  judicious  use  of  strong  liquors,  or  ^ooze,' 
obtained  from  finely-ground  bark,  and  by  skilful  tanning. 

The  loss  and  wastage  upon  hides,  from  hair,  flesh,  &c., 
may  be  estimated  at  from  12  to  15  per  cent.  In  order 
to  produce  heavy  weights,  the  hides  should  not  be  re- 
duced too  low  in  the  beam-house,  and  should  be  tanned 

for  the  last  time,  and  tlien  placed  in  pits  in  the  ordinary  way,  to  remain 
in  them  for  from  two  to  three  months,  according  to  their  thickness  and 
size.  Instead,  however,  of  filling  up  the  pits  with  pure  water,  or  a  weak 
tan  liquor,  which  may  both  retard  the  operation  and  injure  the  skins,  it 
is  recommended  to  use  a  concentrated  infusion  of  bark  alone. 

The  fulling-mill  used  in  the  American  tanneries  is  similar  in  construc- 
tion to  the  preceding.  The  drawing  (Fig.  112),  for  which  we  are  in- 
debted to  the  Messrs.  Wiltse,  machinists,  represents  the  machine  upon 
the  scale  of  a  quarter  of  an  inch  to  the  foot.  If  driven  by  an  engine  or 
by  a  belt,  the  wheels  ^and  I,  with  the  pulley  J",  are  used.  When  water- 
power  is  employed,  they  are  replaced  by  a  water-wheel  K,  built  upon 
the  same  shaft  A.  The  width  of  the  wheel  should  be  four  feet,  and  it 
should  run  at  the  rate  of  twenty  revolutions  per  minute. 

The  hammers  C,  of  the  mill  are  secured  in  the  arms  D,  which,  by 
coming  in  contact,  at  their  lower  ends,  with  the  tappets  B,  receive  motion. 
The  upper  ends  of  the  arms  are  hung,  and  work  on  the  nozzle-pin  Ly 
which  passes  through  the  back-piece      of  the  stock-frame  E  F. 

Isaac  S.  Hershey  (^Patent  Office  Report,  1849,  p.  316)  has  patented  a 
machine  for  softening  hides,  which  consists  of  right  and  left  revolving 
helical  breakers  or  fluted  rollers. 

Either  of  these  machines  will  perform  work  much  more  rapidly  and 
satisfactorily  than  it  was  formerly  done  by  the  tedious  and  laborious  pro- 
cess of  treading  the  hides  under  feet. 


326 


HEMLOCK  TANNING. 


quickly  with  good  strong  liquors,  particularly  in  the 
latter  stage  of  the  operation.  To  green  hides,  particu- 
larly, nothing  can  be  more  injurious  than  to  suffer  them 
to  remain  too  long  in  weak  '  ooze.'  They  become  too 
much  reduced,  grow  soft,  flat,  and  flabby,  lose  a  portion 
of  their  gelatine,  and  refuse  to  'plump  up/ 

"On  the  other  hand,  however,  the  eflects  of  an  early 
application  of '  ooze,'  that  is  too  strong  and  too  warm,  to 
green  hides,  is  very  injurious.  It  contracts  the  surface, 
fibres  of  the  skin,  tanning  at  once  the  external  layers  so 
Mead,'  as  it  is  termed,  as  to  shut  up  the  pores,  and  pre- 
vent the  tannin  from  penetrating  the  interior.  This 
renders  the  leather  harsh  and  brittle.  It  will  from  this 
be  seen  that,  in  the  question  of  the  proper  strength  of 
liquor  alone,  there  is  room  for  the  exercise  of  the  greatest 
judgment  and  the  most  extensive  experience.  In  the 
impossibility  of  adapting  fixed  rules  to  the  innumerable 
variety  of  cases,  nothing  can  be  depended  upon  but  the 
judgment  of  the  practical  tanner. 

"  In  softening  hides,  and  preparing  them  for  the  pro- 
cess of  tanning,  a  great  deal  also  depends  upon  the  judg- 
ment of  the  person  superintending  the  operation,  inas- 
much as  the  diversities  in  the  qualities  and  characteristics 
of  hides  render  it  impossible  to  subject  them  to  anything 
more  than  a  general  mode  of  treatment. 

In  '  sweating,'  the  character  of  the  hides,  and  the 
temperature,  are  essential,  but  ever-varing  considerations. 
As  a  general  rule,  however,  the  milder  the  process  of 
preparing  the  hides  for  the  bark,  the  better.  Unneces- 
sarily severe  or  prolonged  treatment  is  inevitably  at- 
tended with  a  loss  of  gelatine,  and  a  consequent  loss  of 
weight  and  strength  in  the  leather.  Too  high  a  temper- 
ature is  particularly  to  be  avoided.  In  almost  every  lot 
of  hides,  particularly  Oronocos,  however,  there  are  gene- 


HEMLOCK  TANNING. 


327 


rally  some  that  prove  very  intractable — resisting  all  the 
ordinary  modes  of  softening.  For  such,  a  solution  of 
ashes,  potash,  or  even  common  salt,  will  be  found  to  be 
beneficial ;  and  peculiarly  so  in  hot  weather.  As  I  have 
said,  no  precise  rule  can  be  given  as  to  the  length  of 
time  required  for  the  preliminary  process  of  soaking  and 
^  sweating,'  so  much  depending  upon  the  qualities  of  the 
hides,  and  the  temperature  at  which  these  oj)erations  are 
conducted. 

"The  following  table  may,  however,  be  found  useful  in 
conveying  an  approximation  to  a  definite  idea  of  the 
practice  in  my  tannery. 

TEMPERATURE. 

SOAKING.  40°  50°         60°  70° 

Days.         Days.       Days.  Days. 

Buenos  Ayres  hides  .  .  10  to  12  8  to  12  6  to  8  3  to  6 
Carthagena  and  Laguaira        .      8  to  12      7  to  9    5  to   7    2  to  3 

SWEATING. 

Buenos  Ayres  hides  .  .  15  to  20  12  to  16  8  to  12  2  to  3 
Carthagena  and  Laguaira        .    15  to  20    10  to  15    6  to   8    2  to  3 

"  I  would  here  remark  that  I  changed  the  process  from 
liming  to  sweating,  for  the  sole  leather,  in  1836 — the 
only  change  in  tanning  I  have  made  for  twenty  years ; 
and  for  heavy  sole  leather,  it  has  been  proved  to  be  quite 
as  good  as  liming  if  not  better,  and  somewhat  cheaper; 
besides  yielding  a  greater  gain  of  weight,  and  when  well 
tanned,  making  leather  more  impervious  [to  water. 
Liming  and  ^bating,'  however,  for  upper  and  light 
leather,  is  preferable;  and,  if  the  same  improvements 
had  been  adopted  with  the  lime  process,  of  strong  liquor 
and  quick  tanning,  it  is  not  yet  certain  that  the  same 
results  would  not  have  been  attained. 

"  Salted  hides  do  not  require  more  than  two-thirds  the 
time  to  soak ;  but  generally  rather  longer  to  sweat.  After 


328 


HEMLOCK  TANNING. 


the  hides  are  prepared  for  tanning,  the  next  process  is 
what  is  commonly  called  ^handling/  which  should  be 
performed  two  or  three  times  a  day  in  a  weak  ^  ooze/  until 
the  grain  is  colored.  New  liquors,  or  a  mixture  of  new 
and  old,  are  preferable  for  Spanish  or  dry  hides — old 
liquor  for  slaughter.  They  are  then,  after  a  fortnight, 
laid  away  in  bark,  and  changed  once  in  two  or  four 
weeks,  until  tanned.  Much  care  and  judgment  are 
necessary  in  proportioning  the  continually  increasing 
strength  of  the  liquors  to  the  requirements  of  the 
leather  in  the  different  stages  of  this  process. 

"  The  liquors  should  also  be  kept  as  cool  as  possible, 
within  certain  limits,  but  ought  never  to  exceed  a  tem- 
perature of  eighty  degrees ;  in  fact,  a  much  lower  tem- 
perature is  the  maximum  point,  if  the  liquor  is  very 
strong;  too  high  a  heat,  with  a  liquor  too  strongly 
charged  with  the  tanning  principle,  being  invariably 
injurious  to  the  life  and  color  of  the  leather.  From  this 
it  would  seem,  that  time  is  an  essential  element  in  the 
process  of  tanning,  and  that  we  cannot  make  up  for  the 
want  of  it  by  increasing  the  strength  of  liquor,  or  rais- 
ing the  temperature  at  which  the  process  is  conducted, 
any  more  than  we  can  fatten  an  ox  or  horse  by  giving  ^ 
him  more  than  he  can  eat. 

I  have  mentioned  the  injurious  effects  resulting  from 
too  strong  a  solution  of  the  active  principle  of  the  bark ; 
on  the  other  hand,  the  use.  of  too  weak  solutions  is  to  be 
avoided.  Hides  that  are  treated  with  liquor  below  the 
proper  strength  become  much  relaxed  in  their  texture, 
and  lose  a  portion  of  their  gelatine.  The  leather  neces- 
sarily loses  in  weight  and  compactness,  and  is  much 
more  porous  and  pervious  to  water.  The  warmer  these 
weak  solutions  are  applied,  the  greater  is  this  loss  of 
gelatine.    To  ascertain  whether  a  portion  of  weak  liquor 


HEMLOCK  TANNING. 


329 


contains  any  gelatine  in  solution,  it  is  only  necessary  to 
strain  a  little  of  it  into  a  glass,  and  then  add  a  small 
quantity  of  a  stronger  liquor.  The  excess  of  tanning  in 
the  strong,  seizing  upon  the  dissolved  gelatine  in  the 
weak  liquor,  will  combine  with  it,  and  be  precipitated 
in  flakes,  of  a  dark  curdled  appearance,  to  the  bottom. 
At  the  Prattsville  Tannery,  the  greatest  strength  of 
liquor  used  for  handling,  as  indicated  by  Pike's  bark- 
ometer,'^'  is  sixteen  degrees;  of  that  employed  in  laying 


*  Hydrometer. — A  hydrometer  is  a  convenient  apparatus  for  ascer- 
taining readily  the  density  or  strength  of  liquids.     That  referred  to 
above  has  been  styled  by  its  maker  (W.  Pike,  of  New  York)  a  harh- 
ometer,  because  it  is  specially  adapted  to  testing  the  strength  of  bark 
lyes.    Its  form  and  the  manner  of  using  it  are  repre- 
sented by  Fig.  113.    It  is  made  whol  ly  of  glass ;  a,  dy 
being  the  stem,  inclosing  a  graduated  paper  scale ;  B, 
a  spherical  bulb ;  and  c,  a  smaller  bulb  at  its  base,  con- 
taining quicksilver  or  shot,  which  serves  as  ballast  to 
retain  the  instrument  in  a  vertical  position  in  the 
liquid.     The  scale  on  the  stem  is  equally  divided 
into  five  or  ten  wide  spaces,  and  each  of  these  again 
subdivided  into  ten  narrow  spaces.    The  zero  point 
of  the  scale  is  made  by  plunging  the  instrument  in 
distilled  water  at  58°  F.,  and  adding  mercury  to  the 
bulb  until  it  sinks  to  nearly  the  top  of  the  stem  a. 
A  solution  of  ten  parts  of  bark  in  ninety  parts  of 
distilled  water  having  been  made,  the  hydrometer  is 
then  plunged  in  the  liquor,  and  the  point  to  which  it 
sinks  therein,  say  5,  is  carefully  and  accurately  marked 
upon  the  scale,  and  rated  as  10  compared  with  the 
zero  point.     Each  of  the  grand  divisions,  conse- 
quently, represents  ten  per  cent,  of  bark,  and  each  of 
the  smaller  ones  or  subdivisions  corresponds  with  one 
per  cent,  of  bark.    It  is  very  easy,  therefore,  after  having  determined 
the  length  of  the  stem  from  zero,  which  sinks  in  a  normal  solution  of 
bark,  to  apportion  the  rest  of  it  with  the  aid  of  a  pair  of  dividers ;  so 
that  every  interval  thus  apportioned  shall  be  equal  to  that  fixed  by  ex- 

22 


330 


HEMLOCK  TANNING. 


away,  the  greatest  strength  varies  from  thirty  to  forty- 
five  degrees. 

"After  the  leather  has  been  thoroughly  tanned  and 
rinsed,  or  scrubbed  by  a  brush  machine  or  broom,  it  will 
tend  very  much  to  improve  its  color  and  pliability  to 
stack  it  up  in  piles,  and  allow  it  to  sweat  until  it  becomes 
a  little  slippery  from  a  kind  of  mucus  that  collects  upon 
its  surface.  A  little  oil  added  to  this  stage  of  the  process, 
or  just  before  rolling,  is  found  to  be  very  useful. 

"  Great  caution  is  necessary  in  the  admission  of  air  in 
drying  when  first  hung  up  to  dry.  No  more  air  than  is 
sufficient  to  keep  the  sides  from  moulding,  should  be 
allowed.  Too  much  air,  or,  in  other  words,  if  dried  too 
rapidly  in  a  current  of  air,  will  injure  the  color,  giving 
a  darker  hue,  and  rendering  the  leather  harsh  and  brittle. 
To  insure  that  the  thick  parts,  or  butts,  shall  roll  smooth 
and  even  with  the  rest  of  the  piece,  it  is  necessary  that 
the  leather  should  be  partially  dried  before  wetting  down 
for  rolling,  and  that,  when  wet  down,  it  should  lay  long 
enough  for  every  side  to  become  equally  damp  throughout. 

"  The  following  table,  condensed  from  the  tanning  records 
of  200,000  hides,  exhibits  the  time  required  to  tan  the 

periment.  When,  therefore,  this  instrument  sinks  into  a  bark  liquor  to 
twenty  degrees,  thirty,  or  any  other  degree,  the  number  indicates  the 
percentage  of  tanning  force.  It  is  necessary  to  observe  that  this  in- 
strument is  applicable  only  to  freshly  made  liquors ;  for  otherwise,  con- 
fusion and  want  of  confidence  might  ensue  upon  finding  that  it  sinks, 
sometimes,  to  a  corresponding  degree  in  spent  liquor.  This  is  owing  to 
the  fact  that  the  alterations  which  tanning  liquors  undergo  during  use 
and  exposure,  may  not  diminish  their  density,  though  they  impair  or 
destroy  their  tanning  power. 

Baume's  hydrometer,  which  is  frequently  mentioned  throughout  this 
book,  is  similarly  constructed,  but  with  scales,  difi"ering  in  graduation 
with  the  kinds  of  liquid  for  which  it  is  to  be  used.  For  full  descriptions 
of  these  instruments,  see  Encyclopedia  of  Chemistry,  p.  717,  and 
Morfit's  Applied  Chemistry,  p.  296. 


HEMLOCK  TANNING.  331 

various  descriptions  of  hides  at  my  establishment,  during 
a  period  of  four  years — it  will  be  seen  that  the  same 
descriptions  of  hides  require  different  times  in  different 
years.  This  is  owing  mainly  to  the  difference  in  the 
temperature  and  weather  of  the  several  seasons,  and  the 
quantity  of  sides  and  strength  of  liquor  in  the  vats,  and 
partly  to  the  different  conditions  and  qualities  of  the 
different  lots  of  the  same  description  of  hides. 


No  of 

Time  of  tanning. 

sides. 

mo. 

ds. 

1841 — San  Juan 

.  7,500 

4 

20 

Orinoco  . 

.  3,500 

5 

15 

.  1,900 

6 

.  9,000 

6 

10 

Laguaira  . 

.  22,000 

7 

15 

Orinoco  . 

.  6,500 

5 

15 

Matamoras 

.  1,100 

5 

u 

.  2,300 

5 

20 

San  Juan 

.  6,500 

4 

15 

Montevideo 

.  5,800 

4 

1842— Honduras 

.  3,600 

6 

20 

Buenos  Ayres  . 

.  10,500 

6 

10 

Chagres  . 

.  1,700 

6 

1843— Orinoco  . 

.  1,100 

5 

Montevideo 

.  2,700 

5 

Eio  Grande 

.  5,800 

4 

20 

1844 — Buenos  Ayres  . 

.  6,500 

6 

20 

Orinoco  . 

.  5,400 

7 

California 

.  1,200 

6 

20 

Buenos  Ayres  . 

.  900 

7 

10 

a 

.  6,500 

5 

10 

1845 — Orinoco  . 

.  1,500 

4 

20 

Rio  Grande 

.  2,100 

5 

.  4,000 

5 

10 

Orinoco  . 

.  2,800 

6 

10 

Laguaira  . 

.  5,100 

7 

Rio  Grande 

.  1,100 

7 

Buffalo  . 

.  2,000 

5 

Buenos  Ayres  . 

.  2,000 

6 

Rio  Grande      .   ^  . 

.  8,500 

6 

10 

332 


HEMLOCK  TANNING. 


From  the  above  table,  it  will  be  seen  the  average  time 
of  tanning  in  1842,  was  five  months  and  seventeen  days; 
of  1843,  five  months  and  twenty-two  days ;  of  1844,  six 
months;  and  of  1845,  six  months  and  eleven  days. 
Average  of  the  whole  time,  five  months  and  twenty-seven 
days.  The  average  weight  of  the  leather  was  over 
eighteen  and  one-half  pounds  per  side.  This,  according 
to  the  best  authorities  we  have  at  hand,  is  considerably 
below  the  time  employed  in  England.  There,  it  is  no 
uncommon  thing  for  eight  and  ten  months  to  be  em- 
ployed in  tanning  a  stock  of  leather,  and  some  of  the 
heaviest  leather,  it  is  said,  takes  even  fourteen  and  eight- 
een months.  Such  deliberation  undoubtedly  insures  a 
fine  quality  of  leather,  but  it  may  be  questioned  whether 
there  is  not  a  great  loss  of  weight — a  loss  of  interest  on 
capital,  and  in  consequence  an  unnecessary  enhancement 
of  price,  which  does  not  suit  the  American  market. 

In  order  to  show  the  amount  of  business  done,  I  have 
carefully  collected  and  tabularized,  from  my  books,  the 
following  statistics  of  the  '  Prattsville  Tannery'  for  twenty 
years,  in  tanniug  about  1,000,000  sides  of  sole  leather: — 

Statistics  of  the  Prattsville  Tannery  for  twenty  years — various  materials 
used  and  labor  employed. 

3,666  acres  of  bark  land — 10  square  miles,  18  cords  to  tlie 


acre— 120,000;  at  $3  per  cord           .       .       .       .  $360,000 

No.  of  days'  work  peeling  and  piling  do.          ...  118,555 

4  trees  to  the  cord   475,200 

120,000  loads,  or  cords— 264,000,000  lbs.       .       .       .  132,000 

1,444  acres  of  wood  land — 32,000  loads,  or  cords,  worth  .  32,000 

35,380  bushels  of  oats,  2,6  per  bushel     ....  41,967 

1,200  tons  of  hay  at  $8  per  ton   9,600 


313,000  days'  work  in  tannery~l,000  years'  labor  at  $14 

per  month  $162,000 

Board  at  $1,50  per  week       ....  78,000 

  240,000 


HEMLOCK  TANNING.  333 

500,000  hides,  weighing  15,000,000  lbs.        .       .       .  1,750,000 

Cartage,  5,700  loads  of  2,600  lbs.  each  (one  pair  horses). 

1,000,000  sides  sole  leather,  at  18  lbs.  per  side       .       .  18,000,000 

Hides  and  leather,  together   33,000,000 

Cost  of  carting   52,800 

3,000  lbs.  per  load  of  leather,  one  pair  of  horses  $6,000 
2,600  lbs.  per  load  of  hides,  one  pair  of  horses  5,700 

  11,700 

Freight  of  hides  and  leather  between  New  York  and  Cat- 
skill    30,000 

Equal  to  118,000,000  leather,  at  7  cts.  per  pound    .       .  3,060,000 

Lost  and  worn  out  about  100  horses,  at  $75  each      .       .  7,500 

Cost  of  wagons,  at  $250  per  year            ....  5,000 

Insurance  on  stock         .......  12,000 

Yearly  expenses   300,000 

Total  expenses,  about   6,000,000 


"  And^  in  justice  to  my  workmen,  I  ought  to  say,  with- 
out the  use  of  ardent  spirits,  or  ever  having  a  side  of 
leather  stolen. 

"A  glance  at  this  table  will  at  once  convince  any  one 
that  the  advantages  of  such  an  establishment  are  not 
confined  to  the  amount  of  value  produced.  The  labor 
employed  directly  or  indirectly  may  be  set  down  at  two 
hundred  men  daily.  The  ramified  branches  of  business 
and  trade  that  it  fosters;  the  comfort,  refinement,  and 
intelligence  of  which  it  becomes  the  centre;  and  its  final 
influence  upon  the  growth  and  populousness  of  the  sur- 
rounding district,  cannot,  I  think,  be  too  highly  estimated. 
The  following  table  shows  but  one  single  item — the 
amount  of  labor  employed  within  the  walls,  or  that  which 
is  directly  and  immediately  employed  in  the  process  of 
-  tanning ;  but,  from  a  comparative  inspection  of  it,  and 
the  table  above,  some  idea  may  be  formed  of  the  amount 
of  labor  indirectly  engaged. 


334 


HEMLOCK  TANNING. 


Average  numher  of  men  employed  at  the  PrattsviUe  Tannery  throughout 
the  year  with  their  respective  wages  per  month. 

Beam-house. 

No.  of  hands.       Pay  per  month. 

Foreman  1        $32  $32 

Chorsemen  .....     2  12  and  board  6,  36 

Beamsmen  12  14         "  180 


In  the  Yard. 


Foreman  ..... 

1 

50 

50 

Handling  and  laying  away  . 

8 

12  and  board  6,  144 

Brushing  leather 

6 

12 

a 

72 

Nightman  to  leeches 

1 

14 

(( 

18 

Grinding  bark  by  day  . 

1 

12 

u 

18 

Grinding  bark  by  night 

1 

14 

u 

20 

Wheeling  bark  .... 

4 

12 

iC 

72 

Filling  and  pitching  leeches  . 

3 

24 

u 

60 

Drying  Loft. 

Foreman  ..... 

1 

20 

a 

26 

Sponger   

1 

12 

u 

18 

Rollers  ..... 

2 

15 

a 

42 

Hanging  up  and  taking  down  leather 

2 

12 

a 

36 

Miscellaneous. 

Foreman  out  doors 

1 

41 

u 

47 

Carpenter  ..... 

1 

39 

(C 

45 

Teamsters  ..... 

12 

11 

a 

218 

Total  

58 

$1120 

500  cords  of  bark  at  $3  per  cord 
Cartage,  repairs,  &c.  &c. 


Grand  total  per  month 


1500 
500 

$3120 


"In  the  following  table,  I  have  given  a  condensed  view 
of  the  operations  at  my  tannery  during  five  years : — 


HEMLOCK  TANNING. 


335 


No.  of  hides  re- 
ceived at  the 
tannery. 

Weight  of 
hides. 

Cartage  in 
New  York. 

Commissions. 

Total  value 
of  hides. 

1841 
1842 
1643 
1844 
1845 

30,984 
27,194 
28,433 
86,839 
20,556 

724,168 
601,595 
630,192 
812,403 
460,798 

$291  47 

275  89 
213  24 

276  28 
154  17 

$5701  47 
3938  30 
4425  64 
5718  36 
2920  25 

$108,758  06 
82,705  01 
78,198  03 
100,982  60 
51,176  60 

Total 

144,006 

3,229,155 

$1211  05 

$22,904  02 

$421,810  52 

Leather  returned  to  New  York. 


Sides. 

Pounds. 

Average 
weight 
per  side. 

Average 
net 
price. 

Commissions. 

Net  proceeds. 

1841 
1842 
1843 
1844 
1845 

Total 

61,729 
54,323 
56,742 
73,590 
40,891 

l,211,856i 
995,0571 
1,061,5231 
1,310,779 
737,789 

29.63 
18.32 
18.71 
17.81 
18.03 

14  44 
13  93 
13  69 
12  55 
11  16 

$7352  24 
5827  08 
6053  42 
6895  25 
3420  57 

$175,018  54 
138,581  05 
144,331  83 
164,517  53 
81,595  26 

287,275  5,316,789 

i 

18.51 

$13  34 

$29,548  66 

$704,044  21 

"  The  tanning  of  leather,  more  than  almost  any  other 
manufacture,  is  a  chemical  process,  the  success  of  which 
depends  almost  wholly  upon  the  skill  and  judgment  with 
which  its  complicated  manipulations  are  conducted.  To 
attain  the  requisite  skill  in  the  laboratory  of  the  chemist, 
is  evidently  impossible ;  it  can  only  be  acquired  in  the 
tanning  itself,  by  long  and  careful  attention  and  ob- 
servation. 

"The  following  tables  present  some  facts  which  may 
be  of  general  interest. 


336 


HEMLOCK  TANNING. 


1 

2 

3 

4 

5 

1836 

2151 

48,130 

22  i 

6594 

71 

1837 

2305 

53,172 

23 

5686 

9 

3118 

59  283 

19 

4991 

10 

1839 

2984 

59,675 

20 

6276 

9 

1840 

3089 

50,514 

m 

6207 

13,647 

270,774 

20 

29,752 

9 

6 

7 

8 

9 

1836 

397 

3573 

50,808 

901,296 

1837 

500 

4500 

50,947 

815,152 

1838 

496 

4464 

50,750 

812,000 

1839 

558 

5022 

56,096 

945,221 

1840 

590 

5310 

57,601 

1,009,609 

2541 

22,869 

266,202 

4,483,378 

"Note. — Column  1,  shows  the  number  of  days'  work 
in  the  beam-house;  2,  number  of  sides  worked  in;  3, 
average  per  man  per  day;  4,  number  of  days'  work  grind- 
ing bark  and  tanning;  5,  average  per  man  per  daj^;  6, 
number  of  leeches ;  7,  cords  of  bark  used,  at  nine  cords 
per  leech ;  8,  sides  of  leather  tanned ;  9,  pounds  of  leather 
tanned  out. 

"  The  labor  in  the  loft  and  peeling  bark  during  the 
above  five  years,  was  8820  days.  One  man  will  work 
through  the  beam-house  in  one  year  6260  sides.  One 
man  will  tan  and  finish  2228  sides.  One  cord  of  bark 
tans  196  pounds. 

"The  question  has  been  frequently  asked  me,  how 
long  does  it  take  to  tan  sole  leather?  I  answer,  from 
four  to  six  months,  according  to  the  strength  of  the  liquor 
and  number  of  sides  in  the  vats;  and  the  quicker  tanned 


HEMLOCK  TANNING. 


337 


tlie  better.  I  would  here  remark,  that  several  considera- 
tions must  be  noticed  in  order  to  meet  the  questions 
understandingly,  and — 

"1.  I  should  say  that  the  weight  of  the  hides,  every 
one  knows,  if  heavy,  requires  more  time  than  if  compara- 
tively light. 

"2.  If  the  hides  are  fresh,  they  are  capable  of  being 
properly  softened,  and,  if  so,  the  process  of  tanning  may 
be  completed  much  sooner  than  in  the  case  of  old  and 
hard  hides,  that  cannot  be  softened  with  the  same  facility. 

"3.  If  the  hides  have  sufficient  room  in  the  vats,  so  as 
not  to  lay  crowded,  they  will  tan  much  faster. 

"4.  As  the  tanning  advances,  the  liquor  should  be 
renewed  seasonably,  and  its  strength  increased  in  a  ratio 
proportionate  to  each  stage  of  tanning. 

"5.  The  question — is  the  leather  to  be  tanned  so  as  to 
barely  pass  in  market,  or  to  be  well  prepared,  so  as  to 
make  firm  and  solid  leather?  involves  a  consideration  of 
much  importance." 


CHAPTEE  XXIV. 

TANNING  WITH  MYRTLE.    (VACCINIUM  MYRTILUS.) 

Eapenius,  a  tanner  of  Bern-Castel,  upon  the  Moselle, 
has  discovered  that  excellent  leather  can  be  made  by 
tanning  with  the  myrtle  plant.  This  is  collected  with 
the  greatest  advantage  in  the  spring  of  the  year,  because 
it  can  be  dried  and  ground  the  most  easily  at  that  time. 
Three  and  a  half  parts  by  weight  of  this  substance  will 
tan  perfectly  one  part  of  leather,  while  six  parts  of  oak- 
bark  are  required  for  the  same  quantity.  The  use  of 
this  material,  it  is  said,  enables  tanners  to  prepare  leather 
in  four  months  less  than  the  usual  time.  The  commis- 
sion appointed  at  Treves  to  examine  the  leather  made 
by  this  process,  reported  that  they  had  never  seen  a 
better  product,  and  that  each  pair  of  shoes  made  with  it 
would  last  two  months  longer  than  one  made  from  com- 
mon leather;  also,  that  the  skin  from  the  neck,  which  is 
ordinarily  so  difficult  to  work  up,  became  as  strong  and 
elastic  as  other  parts  when  thus  prepared.  The  myrtle 
should  not  be  pulled  up,  but  cut  off,  so  that  the  roots 
may  reproduce  the  following  year.  When  cut,  it  is  not 
injured  by  water,  while  oak-bark  loses  ten  per  cent,  in 
value  by  exposure  to  moisture. 


TANNING  WITH  GRAPE-SKINS. 


339 


TANNING  WITH  GRAPE-SKINS. 

Nachette,  in  a  letter  to  the  editors  of  the  Joimial  of 
Pharmacy ,  August,  1829,  announced  that  a  chemist  near 
Narbonne  had  proposed  to  substitute  grape-stalks  and 
skins  for  oak-bark  in  tanning. 

To  use  his  own  words:  "Many  chemists  have  long 
sought  for  some  economical  substitute  for  oak-bark,  but 
no  one  has  before  thought  of  employing  for  this  purpose 
the  stalks  and  skins  of  grapes. 

"Struck  with  the  inconvenience  of  the  old  method,  in 
regard  to  time  and  expense  of  material,  his  attention 
was  directed  to  this  subject;  and,  having  prepared  skins 
for  tanning  by  the  ordinary  processes,  he  placed  them  in 
vats  filled  with  the  stalks  and  skins  of  grapes — previously 
distilled,  so  as  to  save  the  small  amount  of  alcohol  re- 
maining in  them — and  allowed  them  to  remain  thus 
surrounded,  for  from  thirty-five  to  forty -five  days,  which 
time  he  found  amply  sufiicient.  The  advantages  of  pre- 
paring leather  in  this  way  are  the  following:  1.  Much 
less  time  is  required  for  the  completion  of  the  process. 
2.  A  refuse  material,  abundant  in  some  localities,  is  sub- 
stituted for  the  expensive  oak-bark.  3.  A  leather  is 
procured  which  possesses  an  agreeable  but  only  slightly- 
perceptible  odor,  instead  of  having  the  rank,  unpleasant 
smell  of  that  prepared  with  tan,  which  impregnates  the 
persons  and  clothes  of  all  those  engaged  in  its  manufac- 
ture. 4.  Experience  has  proved  that  it  is  leather  of  the 
best  possible  quality,  shoes  made  of  it  lasting  twice  as 
long  as  those  prepared  with  ordinary  leather." 


340 


TANNING  WITH  STATICE. 


TANNING  WITH  STATICE,  OR  MARSH  ROSEMARY. 

Tournel's  experiments  and  process  for  tanning  skins 
by  means  of  statice-root,  which  we  shall  now  give  in 
detail,  are  extracted  from  a  paper  written  by  him  on 
the  subject. 

M.  Gayraud  and  I  commenced  an  experiment  with 
an  ox-hide,  while  Messrs.  Malaret,  tanners  and  curriers, 
of  the  same  town,  undertook  to  prepare  some  goat-skins. 

"Gayraud  followed  the  same  course  in  preparing  the 
hide  as  with  the  bark  of  the  root  of  kermes-oak,  except 
that  he  divided  it  into  two  exactly  equal  portions,  and 
tanned  one  with  statice  and  the  other  with  the  root  of 
the  kermes-oak,  in  order  to  determine  what  difference  in 
weight  would  be  produced  by  the  different  materials. 

"  Six  months  had  elapsed,  when  the  heat  of  the  wea- 
ther produced  in  the  statice  liquor  so  active  a  fermenta- 
tion as  to  burst  the  containing  vessel  and  spill  the 
contents,  thus  making  it  impossible  to  carry  out  fully 
this  first  experiment.  The  tannin,  however,  had  pene- 
trated nearly  to  the  centre,  and  the  thinner  parts  were 
already  perfectly  tanned,  and  probably  an  additional 
exposure  of  only  two  months  would  have  completed  its 
conversion  into  leather.  This  leather  was  given  to  M. 
Camp,  master  shoemaker  of  the  town,  who  asserted, 
after  thorough  examination,  that  it  was  of  the  very  best 
quality.  The  Messrs.  Malaret  also  declared  their  method 
of  tanning  the  goat-skins  to  be  superior  to  that  with 
oak-bark. 

"I  then  succeeded  in  tanning  perfect^,  in  one  year, 
a  piece  of  a  thick  Buenos  Ayres  hide,  which  would  have 


TANNING  WITH  STATICE. 


841 


required  exposure  for  at  least  eighteen  months  in  the 
ordinary  way. 

"  These  successful  results  led  to  experiments  on  a  larger 
scale,  and  M.  Gayraud  commenced  the  tanning  of  more 
than  a  hundred  horse-hides,  and  of  fifty  imported  cow- 
hides; while  Messrs.  Malaret  essayed  with  one  hundred 
and  fifty  goat-skins,  and  M.  Jacques  Galas  with  eighty 
horse-hides;  the  cow-skins  being  intended  for  soles,  and 
the  horse-hides  and  goat-skins  for  upper  leather. 

M.  Gayraud  placed  the  fifty  cow-skins  in  the  lime- 
pit,  to  separate  the  hair  and  raise  them.  As  is  commonly 
the  case  with  imported  hides,  the  liming  revealed  many 
defects  and  injuries  which  were  before  concealed,  so  that 
out  of  the  fifty  hides,  at  least  one-third  were  more  or  less 
damaged,  and  some  of  them  had  to  be  trimmed  to  one- 
half  their  size  in  consequence  of  being  injured.  This 
circumstance  prevented  the  correct  estimation  of  differ- 
ences in  weight  from  the  process,  but  the  satisfaction  was 
left  to  us  of  finding  that  the  statice  having  fermented 
quickly  and  considerably,  these  hides  were  tanned  in  a 
third  less  than  the  usual  time.  Those  which  were 
originally  sound,  were  remarkable  for  weight,  beauty, 
color,  and  strength. 

"M.  Gayraud  was  so  well  satisfied  with  these  results, 
that  he  purchased  a  number  of  perfect  skins  from  the 
neighboring  towns,  and,  after  weighing  them  exactly, 
submitted  them  to  the  action  of  the  statice  in  vats,  and 
obtained  with  it  a  most  satisfactory  result. 

In  the  preparation  of  the  horse-hides,  the  superiority 
of  the  statice  over  ordinary  tan  was  evident  in  the  finer 
structure  of  the  product,  the  shortness  of  the  process,  econ- 
omy of  material,  beauty  of  color,  and  increased  weight,  and 
power  of  absorbing  fatty  bodies.  The  same  advantages 
were  perceived  and  appreciated  by  Messrs.  Malaret,  in 


342      PREPARING  SKINS  BY  MEANS  OF  TAR  AND  SOOT. 

the  goat-leather  tanned  by  them,  and  induced  them  to 
repeat  the  processes  in  other  cases.  The  want  of  access 
to  proper  materials  in  Narbonne  and  its  neighborhood, 
alone  prevented  me  from  extending  these  experiments  to 
calf  and  sheep  skins,  and  those  intended  for  saddlers, 
harness-makers,  and  coach-makers,  but  I  had  already 
received  sufficient  evidence  that  this  method  would  be 
equally  well  adapted  for  all  kinds  of  leather,  and  was 
convinced  that  it  rendered  sole  leather,  particularly,  firm 
and  impenetrable,  while  it  increased  the  pliability  and 
strength  of  that  intended  for  uppers.  Its  advantages, 
then,  are  economy  of  time  and  material,  facility  of  pre- 
paration, softness  and  impermeability  to  water,  beauty  of 
color,  and  durability. 

"All  the  skins  thus  prepared  have  been  sold,  and  the 
workmen  who  have  used  them  have  unanimously  given 
them  the  preference  over  those  made  in  the  usual  man- 
ner. They  are  believed  to  equal  skins  tanned  with 
kermes-oak  bark  for  wear  in  damp  weather,  while  in  dry 
weather  they  are  much  superior  as  to  flexibility ;  and, 
moreover,  they  hold  thread  better,  and  are  more  easily 
worked.  The  leather  for  uppers  is  remarkable  both  for 
suppleness  and  firmness,  and  for  the  brilliancy,  intensity, 
and  durability  of  the  black  color  which  can  be  given 
to  it." 

MODE  OF  PREPARING  SKINS  BY  MEANS  OF  TAR  AND  SOOT. 

Barry's  Process. — The  tan  liquor  for  this  preparation 
is  made  by  mixing  twenty  or  twenty-two  pounds  of 
good  tar  with  105  gallons  of  boiling  water,  and  adding 
enough  lime  to  form  a  thick  paste.  A  quantity  of  cold 
water,  sufficient  to  slack  the  lime,  a  bucket-full  of  lime, 
and  the  same  quantity  of  tar  are  then  added,  and  the 


PREPARING  SKINS  BY  MEANS  OF  TAR  AND  SOOT.  343 


whole  is  thoroughly  stirred  to  the  consistence  of  a  thick 
paste.  This  mixture  is  distributed  in  a  number  of 
vessels,  or  vats,  and  is  thinned  with  boiling  water.  The 
vessels  are  covered,  and  in  twenty-four  hours  their  con- 
tents are  ready  for  use. 

The  soot-liquor  is  prepared  by  mixing  together  110 
pounds  of  soot,  4i  pounds  of  powdered  lime,  and  485 
pounds  of  water,  the  whole  being  stirred  up  during  the 
gradual  addition  of  the  water.  The  vessel  is  covered, 
and  the  liquor  filtered  at  the  end  of  twenty-four  hours. 

Skins  which  are  intended  for  polished  leather,  are 
first  prepared  for  tanning  by  the  ordinary  processes,  and 
are  then  placed  in  cold  vats  of  gallic  acid  and  decoction 
of  bark,  in  which  they  are  allowed  to  remain  four  or 
five  days  or  a  week,  being  taken  out  and  handled  three 
or  four  times  a  day.  They  are  then  deposited  in  the 
warm  tar-liquor,  having,  at  first,  only  one-half  the 
strength  above  stated,  but  which  is  gradually  increased 
to  the  original  degree  of  saturation.  After  fifteen  days, 
the  skins  are  replaced  in  the  vats  and  treated  as  before; 
and  then  deposited  in  weak  tar-liquor,  being  taken  out 
and  replaced  three  or  four  times  a  day  for  the  first  fifteen 
days.  They  are  then  deposited  in  liquor  of  the  full 
strength  and  worked  as  before,  until  they  are  well  pene- 
trated by  it,  and  are  finally  kept  for  a  week  or  more  in 
a  vat  of  hot  decoction  of  coppice  oak  or  sumach,  and 
then  dried. 

Skins  for  sole  leather  are  prepared  in  the  usual  man- 
ner, and  are  then  soaked  for  some  days  in  a  cold  vat  of 
gallic  acid  and  decoction  of  bark,  being  treated  as  is 
directed  for  polished  leather.  They  are  then  immersed 
in  a  warm,  weak  soot-liquor,  of  about  one-third  or  one- 
half  the  strength  above  indicated.  After  having  been 
alternately  taken  out  and  handled  in  this  liquor  three 


344 


TANNING  WITH  FURZE. 


or  four  times  a  day,  they  are  then  deposited  in  a  vat  con- 
taining hot  soot-liquor  of  the  original  strength,  and  are 
worked  in  it  three  or  four  times  daily,  as  above  directed, 
until  completely  saturated.  They  are  then  taken  out 
and  dried,  soaked  in  hot  water  for  half  an  hour,  cleaned 
and  brushed  upon  the  marble  slab  three  or  four  times  on 
both  sides.  Finally,  the  skins  thus  prepared  are  im- 
mersed four  several  times  daily  in  a  strong  hot  ooze, 
until  the  tanning  is  completed ;  care  being  observed  to 
dry  them  after  each  immersion. 

TANNING  WITH  FURZE. 

According  to  Rankin,  the  furze  or  heath  which  is  so 
common  in  Ireland,  contains  a  tanning  principle,  and 
may  be  used  as  a  substitute  for  oak-bark.  Having  suc- 
ceeded in  a  number  of  trials,  he  published  the  following 
process.  The  furze  is  boiled  with  water,  for  three  hours, 
in  a  large  boiler  made  of  any  material  except  iron,  which 
is  suitable  for  the  purpose,  and  the  liquid  is  decanted 
into  large  vats,  so  placed  that  it  can  be  drawn  off  when 
desired.  The  skins  are  then  deposited  in  this  liquid  as 
soon  as  its  temperature  has  fallen  to  about  95°  F.  The 
liquor  must  be  frequently  changed,  the  same  precautions 
being  taken  each  time.  Complete  success  was  attained 
by  this  method,  which  "  feeds"  the  skins  more  rapidly 
than  the  cold  processes. 


CHAPTER  XXV. 


ENGLISH  HARNESS  LEATHER. 

The  fine  brown  leather  made  in  England  for  saddlers' 
use  is  very  highly  esteemed,  and,  notwithstanding  its 
costliness,  is  much  sought  after,  being  superior  to  any 
other  in  suppleness,  density,  and  color.  Its  excellence 
is  not  attributable  to  any  novelty  in  the  processes  em- 
ployed in  its  manufacture,  or  to  the  use  of  complicated 
and  costly  machinery,  but  solely  to  the  care  with  which 
the  materials  are  selected,  and  to  the  skilful  and  accu- 
rate manipulation  of  the  workmen. 

The  finest  skins  used  for  this  leather  come  from  cattle 
raised  in  Wiltshire  and  Somersetshire,  the  climate  and 
pasturage  of  which  counties  seem  to  be  best  adapted  to 
secure  the  development  of  tissue  in  these  animals,  and 
particularly  of  the  firm,  elastic,  and  resisting  integu- 
ments which  are  so  necessary  for  the  production  of  grain 
leather. 

The  preference  is  given  to  the  skins  of  cows  or  of 
young  bulls,  which  are  usually  tanned  in  the  neighbor- 
hood of  Bristol,  and  then  sent  to  London,  where  the 
finest  of  them  are  selected  by  the  manuficturers. 

According  to  Jahkel,  the  processes  of  tanning  to  which 
they  are  subjected  are  in  general  similar  to  those  else- 
where employed,  and  comprehend,  besides  liming  and 
the  separation  of  the  hair,  the  use  of  grainers  of  chicken's 
23 


346 


ENGLISH  HARNESS  LEATHER. 


or  pigeons'  dung,  dipping,  immersion  in  tan-baths  of  dif- 
ferent strengths,  and  two  separate  tannings  in  pits,  with 
fresh  bark  of  the  finest  quality.  The  currying  which 
the  leather  undergoes  in  order  to  adapt  it  for  the  purposes 
of  the  saddler,  serves  to  remove  its  original  dryness, 
stiffness,  and  depth  of  color,  and  to  render  it  supple, 
elastic,  and  impervious  to  moisture,  without  diminishing 
the  solidity  and  density  of  structure  given  to  it  by  the 
tanning. 

The  leather  is  first  cut  in  half  along  the  length  of  the 
skin,  and  is  then  repeatedly  soaked,  beaten,  and  washed 
in  pure  water,  in  order  to  dissolve  and  remove  the  gallic 
acid  and  extractive  matter,  which,  if  allowed  to  remain, 
might,  by  further  oxidation,  deepen  the  color,  and  inter- 
fere with  the  proper  absorption  of  the  substances  which 
are  afterwards  applied.  All  foreign  bodies  having  been 
removed  by  these  means,  the  skins,  although  saturated 
with  the  tannin  of  oak-bark,  are  yet  in  a  condition 
which  enables  them  to  absorb  sumach;  and  they  are 
accordingly  deposited  in  a  bath  containing  one-quarter 
of  their  weight  of  powdered  sumach.  The  leather  is 
taken  out  and  dipped  again  in  a  new  position,  two  or 
three  times  every  day  while  in  this  bath,  the  powder 
which  has  settled  to  the  bottom  being  stirred  about  each 
time ;  and  at  the  end  of  the  second  day,  a  quantity  of 
sumach,  equal  to  that  originally  deposited,  is  added. 
The  skins  are  taken  out  at  the  end  of  three  days,  which 
time  is  usually  sufficient  for  their  saturation,  and  are 
then  found  to  be  not  only  improved  in  color,  but  to  be 
much  more  soft  and  pliable  than  before  the  treatment. 

In  order  still  more  completely  to  develop  the  peculiar 
bistre-like  yellow  tint  of  these  skins,  which  constitutes 
their  beauty,  they  are  washed  in  water  to  remove  excess 
of  sumach,  &c.,  and  then  passed  repeatedly  through  a  very 


BUTTS,  CALLED  RED  LEATHER. 


347 


weak  bath  of  sulphuric  acid,  being  quickly  taken  out 
after  each  immersion,  and  immediately  afterwards  well 
rinsed  in  pure  water,  to  dissolve  out  the  acid,  which,  if 
allowed  to  remain,  might  act  injuriously. 

The  leather  is  then,  after  being  dried,  oiled  upon  the 
flesh  with  pure  cod-liver  oil,  and,  when  thoroughly  pene- 
trated by  this,  with  a  mixture  of  the  best  quality  of 
whale-oil  with  half  its  weight  of  tallow;  being  in  the 
mean  time  scraped  as  usual  upon  the  grain  with  the 
fleshing-knife.  It  is  then  pared,  slicked,  and  beaten 
out  flat ;  all  these  operations  being  conducted  by  hand, 
and  not,  as  some  suppose,  by  machinery ;  the  excellence 
of  the  product  depending  entirely  upon  the  skill  and 
attention  bestowed  upon  it  by  the  workman. 

BUTTS,  CALLED  RED  LEATHER. 

Butts  from  Buenos  Ayres,  or  from  the  Colonies,  are 
almost  exclusively  used  for  the  manufacture  of  this  kind 
of  leather.  They  are  first  soaked  for  four  or  five  days, 
and  then  deposited  in  an  old  lime-vat,  and  evenly  ex- 
tended, so  that  they  may  not  wrinkle ;  the  hides  of  the 
very  largest  size  being  cut  in  half  along  the  line  from 
head  to  tail.  After  repeated  handling  in  this  pit  for  five 
days,  they  are  taken  out,  freed  from  hair,  and  deposited 
in  a  fresh  vat,  in  which  they  are  allowed  to  remain  two 
or  three  months.  During  this  process,  they  must  be 
handled  twice  a  week,  and  a  little  fresh  lime  should  be 
thrown  in  during  each  of  the  last  five  handlings.  When 
ready  to  be  fleshed,  they  are  taken  out  and  rinsed  four 
times,  only  partially,  so  that  the  lime,  which  is  the  cause 
of  their  rigidity,  may  not  be  entirely  washed  out. 

Being  thus  prepared,  the  hides  are  placed  in  the  pit 
and  stratified,  not,  as  in  the  manufacture  of  common 


348 


BUTTS,  CALLED  BED  LEATHER. 


leather,  with  the  bark  of  oak  branches,  but  with  the 
bark  of  the  root  of  the  evergreen,  or  scarlet  oak,  which 
has  been  soaked  in  water.  After  being  left  for  three 
months  in  the  first  pit,  they  are  placed  in  a  second  one, 
in  which  they  are  exposed  to  the  action  of  the  bark  for 
the  same  length  of  time,  and  then  are  taken  out,  dried, 
and  delivered  to  the  currier.  About  120  lbs.  of  this  kind 
of  bark  are  required  for  each  hide. 


CHAPTER  XXYI. 

CALF-SKINS. 

The  tanning  of  calf-skins  is  conducted  much  in  the 
same  way  as  that  of  small  cow-hides.  After  having  been 
pressed,  to  expel  oleaginous  matters,  they  are  passed 
three  times  through  old,  and  once  through  fresh  lime- 
vats;  but  being  too  weak  to  bear  the  full  strength  of  the 
lime,  this  should  be  done  after  the  passage  of  cow-skins 
through  the  vats  has  somewhat  diminished  its  activity. 
If  they  are  dry  when  they  enter  the  tannery,  they  should 
be  first  trodden  out  and  soaked.  They  are  then  freed 
from  their  lime  by  the  scraper,  carefully  fleshed,  and 
rinsed,  after  which  they  are  ready  for  a  part  of  the  pro- 
cess, which  difiers  from  that  used  for  cow-skins. 

This  consists  in  placing  from  fifteen  to  eighteen  skins 
in  a  tub,  and  beating  them  for  eight  or  ten  minutes. 
This  operation,  which  softens  the  fibre,  should  be  re- 
peated after  each  rinsing,  though  it  is  omitted  in  the 
establishments  where  the  skins  are  rinsed  as  often  as  six 
times.  The  beaters  are  wedge-shaped,  and  from  8i  to  10 
inches  in  height. 

After  the  skins  are  entirely  free  from  hair  and  lime, 
they  are  placed  in  the  hot  ooze  and  water,  and  treated 
like  cow-skins,  excepting  that  they  require  more  frequent 
and  careful  handling.  Care  should  also  be  taken  to  put 
fresh  tan  each  time  into  the  vats.    They  are  then  sub- 


350 


CALF-SKINS. 


jected  to  the  action  of  stronger  ooze  and  tan,  in  the  same 
manner  as  other  skins,  for  a  month,  and  are  afterwards 
transferred  to  the  pits.  In  these,  unlike  crop-leather 
and  hides,  they  are  folded  lengthwise  and  unequally,  and 
thus  spread  over  with  tan,  care  being  taken  to  cover 
the  heads  and  tails,  as  being  the  thickest  portions,  with 
rather  more  tan  than  the  other  parts.  The  tan  used  for 
calf-skins  should  be  of  the  very  finest  quality.  Expo- 
sure in  the  first  pit  continues  about  three  months.  They 
are  then  taken  out,  freed  from  all  particles  of  tan  which 
adhere  to  them,  and  placed  in  the  second  pit  with  tan, 
which  is  also  in  the  finest  state  of  division.  They  must 
be  folded  double  and  unevenly  as  before,  but  in  such  a 
manner  that  the  part  before  covered  shall  now  be  ex- 
posed. The  pits  are  then  filled  up  as  usual,  the  w^hole 
moistened  with  w^arm  water,  and  left  for  three  months, 
when  the  skins  may  be  considered  as  ready  to  be  placed 
in  the  hands  of  the  currier. 

Some  manufacturers,  in  tanning  calf  and  sheep  skins, 
use  a  warm  infusion  of  bark  to  moisten  their  pits  with, 
instead  of  cold  water.  This  is  probably  an  improve- 
ment upon  the  old  process. 

As  it  is  all-important  to  have  the  skins  soft  and  in  a 
condition  to  absorb  the  tanning  liquor  readily,  some 
tanners  accomplish  this  end  by  removing  all  traces  of 
opposing  substances,  such  as  lime,  grease,  and  glutinous 
matter,  with  the  aid  of  an  alkaline  lye.  This  alkaline 
lye  consists  of  water  impregnated  with  pigeon's  or  hen's  * 
dung,  and  is  technically  termed  a  grainer,  or  hate.  Ten 
or  twelve  gallons  of  dung  suffice  for  one  hundred  skins; 
and  during  the  time  they  remain  in  the  bate-liquor, 
which  is  generally  from  eight  to  ten  days,  they  must  be 
frequently  handled  and  scraped  on  the  beam.    After  the 


CALF-SKINS. 


351 


action  of  the  bate,  tlie  skins  assume  the  form  of  'pelts^ 
in  which  state  they  are  placed  in  the  ooze-vats. 

The  bate  acts  by  means  of  the  muriate  of  ammonia, 
which  it  contains.  The  lime  in  the  skins  decomposes 
this  muriate  of  ammonia,  takes  its  acid,  and  becomes 
muriate  of  lime,  which  is  soluble,  and  is  carried  away 
by  the  wash  waters,  while  the  ammonia  passes  off  in  a 
gaseous  state.  If  the  bate  consists  of  fresh  d%ing^  the 
organic  matter  contained  in  it  is  liable  to  putrefactive 
fermentation,  which  involves  a  partial  decomposition  of 
the  gelatinous  tissue,  and  consequent  loss,  and  at  the 
same  time  imparts  a  very  undesirable  color  to  the 
leather. 

Kampffmeyer  gives  the  following  results  of  a  series  of 
experiments,  made  by  him  to  determine  the  compara- 
tive availability  of  oak-bark,  catechu,  divi-divi,  and 
alder,  as  tanning  material  for  calf-skins. 

Twenty-five  calf-skins,  as  much  alike  as  possible  in 
appearance,  quality,  and  state  of  dryness,  were  selected, 
and  seven  of  the  number  were  tanned  with  oak-bark, 
six  with  alder-bark,  six  with  catechu,  and  six  with  divi- 
divi.  All  of  these  skins  were  made  to  undergo  the  pre- 
paratory processes  during  the  same  length  of  time,  and 
exactly  in  the  same  manner,  except  that  a  certain  num- 
ber were  limed  in  the  ordinary  way,  and  the  rest  were 
exposed  to  sulphuretted  lime  from  the  gas-works.  After 
being  freed  from  lime,  they  were  simultaneously  deposited 
in  the  different  pits.  The  following  were  the  results  of 
the  tanning  : — 

Oak-bark. — The  three  skins  which  had  been  depilated 
by  "gas-works  lime,"  weighed  originally  14  pounds  2 
ounces.  After  being  tanned  and  tallowed,  they  weighed 
13  pounds  9  ounces,  showing  a  loss  of  19  ounces.  The 
quantity  of  oak-bark  used  was  95  pounds. 


352 


CALF-SKINS. 


The  four  skins  treated  with  quicldime  weighed  ori- 
ginally 16  pounds  3  ounces,  and  lost  15  ounces  by  the 
tanning.  These  skins,  which  had  exhausted  118  pounds 
12  ounces  of  tan,  were  found  to  be  very  well  tanned 
and  of  a  finer  grain  than  any  of  the  others.  Those 
prepared  with  "gas-works  lime"  were  firmer,  without 
having  suffered  any  diminution  of  their  softness  and 
pliability,  and  working  with  the  flesh-knife  brought  out 
a  fine  surface. 

Divi-divi, — Of  the  skins  tanned  with  this  material, 
the  three  which  had  been  treated  with  "gas-works  lime" 
weighed  originally  12  pounds  2  ounces,  and  were  found 
to  have  lost  after  tanning  6  ounces;  14  pounds  7  ounces 
of  divi-divi  having  been  used. 

The  others,  which  were  freed  from  hair  by  means  of 
quicklime,  weighed  at  first  11  pounds  9  ounces,  and  lost 
10  ounces.  The  same  proportionate  amount  of  divi-divi 
was  used  as  for  the  others. 

The  color  and  appearance  of  the  leather  were,  in  every 
instance,  most  satisfactory.  The  grain  did  not  look  quite 
as  well  as  that  of  the  leather  tanned  with  oak-bark,  but 
was  sufficiently  fine. 

CatecJiu^  or  Terra  Japonica. — The  three  skins  treated 
with  "gas-works  lime"  weighed  at  first  10  pounds  13 
ounces,  and  gained  10 i  ounces  during  the  tanning;  14 
pounds  7  ounces  of  catechu  having  been  consumed. 

Those  prepared  with  quicklime  weighed  originally  13 
pounds  2  ounces,  and  gained  6  ounces  by  being  tanned. 
The  same  quantity  of  catechu  was  exhausted  as  before. 
These  skins  were  nearly  perfectly  tanned.  Their  color 
was  of  an  orange  hue.  The  flesh  sides  were  uneven  and 
rough,  the  texture  loose  and  spongy,  and  the  grain  much 
inferior  to  that  of  those  treated  with  the  other  materials. 

Alder-hark. — The  three  skins  prepared  with  "  gas-works 


CALF-SKINS.  353 

lime"  weighed  12  pounds  2  ounces,  and  gained  5  ounces 
in  the  tanning,  171  pounds  of  alder-bark  being  used. 
The  three  which  were  limed  in  the  ordinary  manner 
weighed  at  first  11  pounds  1  ounce,  and  lost  7  ounces  in 
the  tanning,  and  134  pounds  of  the  bark  were  used  for 
these  skins. 

Notwithstanding  the  very  large  quantity  of  bark  em- 
ployed, all  of  the  skins  were  imperfectly  tanned,  particu- 
larly those  which  were  treated  with  lime  from  the 
gas-works.  They  w^ere  so  hard  and  dense  as  to  be  im- 
pervious to  grease.  The  grain  was  bad,  and  brought 
out  with  difficulty,  and  their  stiffness  and  dryness  were 
so  great  that  the  hair  side  cracked  when  the  leather  was 
bent.  They  were  of  a  deep  brown  color,  inelastic,  and 
inferior  in  every  respect  to  all  the  others. 

In  comparing  the  two  modes  of  unhairing  skins,  the 
author  believes  that  the  use  of  gas-lime"  offers  some 
advantages  over  the  old  method  of  depilating  by  quick- 
lime. There  is  little  difference  between  their  cost,  and 
the  skins  treated  with  the  former  are  perhaps  finer,  more 
pliable  and  durable,  and  more  impervious  to  moisture. 

The  results  of  the  experiments  prove  that  the  use  of 
catechu  for  tanning  in  the  dry  way  is  almost  inadmissi- 
ble, giving  rise  as  it  does  to  a  porous  and  loose  condition 
of  the  texture  of  leather.  The  experiments  with  alder- 
bark  were  still  less  satisfactory.  The  skins  tanned  with 
oak-bark  and  divi-divi  were,  on  the  whole,  equally  good ; 
while  there  is  not  much  difference  between  the  actual 
expense  of  these  materials,  since  the  latter,  though  much 
more  costly,  contains  nearly  six  times  as  much  tannin  as 
the  former.  One  objection  to  its  use  arises  from  the  diffi- 
culty of  reducing  it  to  powder  between  the  ordinary 
grindstones,  owing  to  its  coriaceous  and  glutinous  nature. 

Very  nearly  the  same  results  as  those  above  described 


354 


CALF-SKINS. 


were  obtained  by  the  tanning  of  raw  Buenos  Ayres  hides, 
the  divi-divi  preserving  its  character  for  superiority  to 
the  catechu  and  alder,  and  being  equal  in  most  respects 
to  oak-bark.  There  is  more  care  to  be  observed  in  its 
use,  though  it  effects  the  tanning  in  one-third  less  time 
than  oak-bark.  The  best  mode  of  employing  it  is  in  the 
form  of  an  extract,  and  in  combination  with  oak-bark, 
as  is  done  in  England;  the  skins  being  covered  first  with 
a  layer  of  divi-divi,  and  then  with  a  thin  stratum  of  tan. 

According  to  the  author,  the  divi-divi  is  the  only  sub- 
stance that  can  successfully  or  profitably  replace  oak- 
bark,  and  a  reduction  in  the  price  of  the  article  will  pro- 
bably give  rise  to  a  very  general  employment  of  it. 

CALF-SKINS,  IMPROPERLY  CALLED  "ALUMED  SKINS." 

Alumed  calf-skins  are  very  little  used,  and  are  chiefly 
employed  by  bookbinders.  The  secret  of  their  manu- 
facture was  for  a  long  time  unknown;  but  the  following 
account  was  given  by  reliable  persons  to  Delalande,  from 
whose  work  it  is  extracted. 

The  dried  skins  of  stillborn  calves,  or  others  of  low 
price,  are  selected  for  the  manufacture  of  this  so-called 
alumed  leather;  those  which  have  been  injured  by 
weevils  or  worms  being  rejected.  In  opening  them,  they 
are  strongly  beaten  with  a  stick  to  get  rid  of  dust  and 
insects,  and  are  then  deposited  in  a  place  which  must 
not  be  either  too  damp  or  warm. 

Thirteen  dozen  dry  skins  are  worked  at  a  time.  They 
are  deposited  in  an  oval  pit,  dug  out  in  the  ground,  which 
is  from  11  to  13  feet  long,  by  3i  to  4i  feet  wide,  and  6i 
feet  deep.  The  water  is  passed  into  this  pit  through  an 
oval  aperture,  a  foot  and  a  half  in  height,  and  narrow 


CALF-SKINS. 


355 


enough  to  prevent  the  skins  from  escaping  from  it,  and 
drains  away  through  another  similar  opening. 

The  water  used  at  Verneuil,  where  this  kind  of  lea- 
ther was  originally  prepared,  is  supposed  to  possess  pecu- 
liar virtues,  especially  fitting  it  for  the  preparation  of 
these  skins;  and,  for  a  long  time,  the  erroneous  opinion 
was  entertained  that  they  could  only  be  properly  pre- 
pared by  its  use.  Hence  the  precautions  adopted  to 
secure  the  exposure  of  the  skins  to  a  constant  stream 
of  it. 

The  skins  remain  in  the  pit  two  or  three  days  in  sum- 
mer, and  six  or  eight  in  winter.  When  taken  out,  they 
are  stacked,  and  the  next  day  are  scraped  upon  the  horse 
with  a  blunt  knife.  They  are  again  deposited  in  the 
vat,  and  left  during  two  days,  after  which  they  are  scraped 
as  before,  and,  if  not  sufiiciently  softened,  are  exposed  a 
third  time  in  the  pit  for  a  day  and  again  scraped.  They 
are  then  placed  in  the  lime-pit,  which  is  a  hole  from 
41  to  5  feet  in  depth,  and  of  proportionate  length  and 
breadth.  From  40  to  50  buckets  of  water  are  thrown 
into  this  with  a  cask-full  of  lime,  which  is  left  to  slack 
for  12  or  15  hours.  After  this,  the  contents  of  the  pit 
are  thoroughly  stirred  by  means  of  a  long  pole,  while  the 
skins  are  deposited  singly  and  dipped  with  a  stick.  After 
remaining  in  the  lime-pit  for  a  day,  they  are  taken  out, 
spread,  and  stacked,  and  subsequently  passed,  in  the 
same  way,  through  new  lime-pits,  gradually  increasing 
in  strength,  until  the  hair  is  ready  to  be  removed.  They 
are  then  well  washed  in  running  water,  deprived  of  hair, 
and  deposited  again  in  a  vat  similar  to  that  first  described, 
and  allowed  to  soak  over  night,  being  kept  in  position 
by  a  long  heavy  pole  placed  longitudinally  above  them. 
These  operations  concluded,  they  are  well  fleshed  to  the 
quick  with  a  sharp  knife,  upon  the  horse,  until  the  flesh 


356  CALF-SKINS. 

side  can  scarcely  be  distinguished  from  the  grain.  The 
heads  and  necks  are  thinned  down  until  they  become  of 
equal  thickness  with  the  other  parts  of  the  skins,  and 
the  ears  J  tails^  and  other  extremities  are  cut  off,  and  pre- 
served for  the  manufacture  of  glue.  After  being  exposed 
to  the  air  for  a  day,  and  kept  in  the  pit  over  night,  they 
are  again  fleshed,  but  with  a  duller  knife  than  that  first 
used.  They  are  next  returned  to  the  first  pit,  and  left 
over  night  in  the  water,  and  the  hair  side  is  worked  upon 
the  horse  so  as  to  expel  the  last  portions  of  lime.  The 
next  process  is  to  empty  three  or  four  buckets-full  of  dog's- 
dung  or  chicken's-dung  into  a  large  vat,  and  to  mix  it 
thoroughly  with  a  bucket-full  of  water,  which  is  done  by 
the  workman  entering  the  vat  and  stamping  upon  the 
contents  with  his  feet.  Cold  water  is  then  thrown  in 
until  the  vat  is  half  full,  and  hot  water  from  a  large 
boiler  is  mixed  with  it.  After  this,  the  skins  are  thrown 
in,  and  are  stirred  about  in  the  vat  for  some  minutes  with 
large  sticks,  when  the  greater  part  of  the  liquor  is  drawn 
off  into  a  boiler  to  be  heated,  and  the  skins,  after  having 
been  left  for  an  hour,  are  arranged  in  a  corner  of  the  vat, 
and  kept  in  place  by  two  sticks  crossed  over  each  other. 
The  hot  liquor  is  then  poured  into  the  empty  part  of  the 
vat,  a  bucket-full  at  a  time,  being  well  stirred  all  the  time, 
and  mixed  with  the  cold  liquor,  so  as  to  avoid  injuring 
the  skins  by  scalding.  When  the  water  is  sufiiciently 
hot,  the  sticks  are  removed,  and  the  skins  are  forcibly 
stirred  around  in  the  vat  three  or  four  times.  The  liquor 
is  then  returned  to  the  boiler,  and  the  same  process  is 
repeated,  great  care  being  taken  not  to  add  the  hot  water 
too  rapidly  to  the  contents  of  the  vat,  and  to  try  its  tem- 
perature frequently  with  the  hand.  The  skins  are  left 
in  for  half  an  hour. 

The  workman  then  collects  them  together  in  a  corner 


CALF-SKINS. 


357 


of  the  vat,  and  examines  them  carefully,  stretching  them 
in  every  direction,  and  when  he  finds  them  perfectly 
pliable  and  soft,  they  are  ready  to  be  taken  out.  He 
removes,  at  first,  one  or  two  dozen  of  those  which  are 
the  most  advanced  in  preparation,  and  deposits  them  in 
buckets,  after  which  he  empties  the  vat  of  water  as 
before,  and  turns  the  skins  three  or  four  times.  After 
a  quarter  of  an  hour,  the  boiler  is  again  filled,  he  col- 
lects the  skins  together  and  takes  out  more  of  them,  and 
so  on  until  they  are  all  removed  from  the  vat. 

The  greatest  care  is  necessary  on  the  part  of  the 
workman  during  these  operations ;  for,  if  the  skins  are 
allowed  to  remain  in  the  hot  mixture  after  they  have 
reached  the  proper  point,  they  will  be  rapidly  softened 
and  destroyed ;  while  others,  at  the  end  of  the  same  time, 
may  not  have  been  exposed  long  enough  for  their  complete 
preparation.  A  repetition  of  the  processes  described,  con- 
tinued for  six  or  seven  hours,  is  sometimes  necessary  for 
imparting  the  requisite  qualities  to  the  stronger  skins. 
Experience  and  frequent  examinations  of  the  skins 
alone  can  enable  the  workman  to  determine  the  proper 
time  for  removing  them  from  the  vat. 

When  this  part  of  the  process  is  finished,  the  skins, 
as  they  are  taken  from  the  vat,  are  stretched  and 
scraped  upon  the  beam,  in  order  to  soften,  distend,  and 
clean  them ;  and  if  any  are  found  to  be  still  too  firm,  they 
are  replaced  in  the  vat  while  the  rest  are  being  washed. 
The  contents  of  the  vat  are  then  allowed  to  escape 
through  the  bunghole,  and  it  is  well  washed  out  and 
half  filled  with  clean  river-water,  while  a  basket-full  of 
fresh  tan  is  thrown  in.  The  skins  are  then  washed  and 
stirred  about  in  this  water  with  sticks,  and  handled  by 
the  workmen,  and  left  in  the  vat  until  the  next  day, 
when  they  are  taken  out,  drained  upon  the  planks,  and 


358 


CALF-SKINS. 


transferred  to  the  care  of  the  sempstress.  Each  skin  is 
carefully  examined  by  her,  any  holes  which  may  exist 
being  closed;  the  skins,  excepting  the  tail  part,  are  then 
sewed  with  the  flesh  side  outwards,  into  the  form  of  a 
bottle.  For  this  purpose,  she  uses  a  large  needle,  which  is 
flat  at  the  point,  and,  with  a  double  thick  thread,  stitches 
one  part  of  the  skin  at  a  distance  of  one-fifth  of  an  inch 
from  the  edge,  and  the  other  that  of  half  an  inch,  turn- 
ing over  the  latter  upon  the  former  in  a  hem,  but  not 
pressing  it  down  tightly  enough  to  prevent  water  from 
draining  through,  or  to  cause  the  production  of  dark 
spots  and  lines  after  tanning.  A  workman  then  places 
in  each  bag  of  skin  a  quantity  of  tan,  proportioned  to 
its  size,  after  which,  the  sempstress  sews  up  the  tail  part 
close  by  the  hind  legs,  so  as  just  to  permit  the  introduc- 
tion of  a  copper  socket  for  a  wooden  funnel.  The  bags 
are  then  brought  near  to  a  vat  in  which  the  tanning  has 
just  been  completed.  The  sacks  in  this  vat  are  removed 
to  a  rack,  in  order  to  be  unripped.  The  vat  is  left  half 
full  of  the  old  liquor,  and  there  is  then  poured  into  it  a 
quantity  of  hot  fresh  liquor  sufficient  to  make  the  con- 
tents lukewarm.  This  fresh  liquor  is  prepared  by 
pouring  the  contents  of  the  already  tanned  sacks  into  a 
vat  provided  with  an  upright  door  or  partition  at  one 
end,  through  which  the  liquor,  which  has  drained  from 
the  tan,  passes,  and  collecting,  in  the  empty  space,  is 
transferred  to  a  boiler.  The  workman  then  takes  a  bag 
of  skin,  and  empties  into  it,  through  the  funnel,  a  small 
bucket-full  of  water,  and  closes  the  moutb  by  tying  it 
up  with  a  small  strip  or  thong,  which  had  been  previ- 
ously cut  from  the  skin  for  the  purpose,  and  left  hanging 
from  the  tail.  The  bags,  having  each  been  filled  with 
the  same  quantity  of  water,  are  then  placed  in  the  vat  and 
left  for  an  hour,  while  another  portion  of  liquor,  prepared 


CALF-SKINS. 


359 


by  percolating  through  tan,  as  above  described,  is  being 
heated  in  the  boiler.  The  workman,  then  placing  the  bags 
upon  a  rack  at  one  end  of  the  vat  into  which  the  heated 
water  has  been  poured,  fills  them  again  through  the  funnel 
from  his  little  bucket,  tying  them  as  before,  by  which 
they  are  made  to  assume  a  pyramidal  shape  in  the  vats. 
This  operation  is  repeated  a  third  time  at  the  expiration 
of  an  hour,  the  heat  of  the  liquor  being  increased  as 
before.  The  liquor  should  be  less  heated  for  those  skins 
which  have  been  a  long  time  in  the  lime-pits,  than  for 
those  which  have  been  a  shorter  time ;  but  the  skill  ex- 
hibited in  making  this  distinction  can  only  be  acquired 
by  long  experience. 

The  next  day  a  similar  operation  is  performed  in  a 
third  vat,  while  the  bags  deposited  the  day  before  are 
left  to  soak  in  the  vat.  The  third  day  the  skins  of  the 
first  vat  are  taken  out  and  left  to  drain  upon  a  rack 
placed  over  the  vat.  They  are  then  thrown  upon  the 
rack  in  the  vat,  upon  which  they  are  unripped  and 
emptied  of  their  tan.  They  are  then  folded  with  the 
flesh  side  within,  and  well  washed  in  running  water ; 
they  are  placed  upon  a  trestle  to  drain ;  are  opened  at 
the  hind  quarters,  and  hung  up  in  a  shed,  with  their 
heads  down,  on  nails  placed  some  distance  apart. 

When  dry,  they  are  piled  up  and  left  until  ready  to 
be  sent  to  market.  They  are  then  moistened,  if  in 
summer,  by  exposure  to  the  dew  of  night  air ;  are  trod 
out  by  workmen  with  heavy  shoes,  in  order  to  render 
them  supple,  and  to  efface  the  marks  of  the  sewing; 
and  are  assorted,  according  to  size,  into  packs  of  six 
each,  which  are  tied  together  by  the  heads  with  pack- 
thread. 

The  greatest  care  is  required  in  all  these  processes  not 
to  allow  the  skins  to  remain  too  long  in  the  dung  mix- 


360 


CALF-SKINS. 


tures,  or  to  permit  the  water  employed  to  be  too  hot, 
since  either  of  these  circumstances  will  make  them  so 
soft  as  to  be  easily  torn.  Those  prepared  with  chicken- 
dung  are  so  thin  as  to  be  almost  transparent.  Manu- 
facturers have  the  idea  that  lightning  and  fogs  injure 
these  skins,  or  interfere  with  their  preparation,  and 
usually  carry  on  their  manufacture,  as  much  as  possible, 
in  spring  and  autumn.  The  hog-skins  used  by  book- 
binders for  Bibles  and  church-books  are  prepared  in  the 
same  manner  as  the  calf-skins,  but  they  differ  from  them 
in  being  exceedingly  thick  and  strong. 

The  tanned  sheep-skins,  used  by  bookbinders,  are  not 
alumed  like  the  calf-skins,  but  are  only  limed  and  tanned. 
Some  of  these  are  sewed  up  and  tanned  similarly  to  the 
calf-skins,  while  others  are  tanned  by  stratifying  them 
with  bark. 


CHAPTER  XXVII. 


TANNING  OF  GOAT  AND  SHEEP  SKINS. 

Goat  and  sheep  skins  are  converted  by  the  tanners 
into  true  Morocco,  imitation  Morocco,  shiver,  and  roan. 

True  Morocco. — Owing  to  the  comparative  scarcity  of 
goatSj  the  tanners  use  very  few  fresh  skins,  their  supplies 
being  drawn  from  Switzerland,  Germany,  Africa,  East 
Indies,  and  Asia  Minor.  As  imported,  they  are  dry, 
and  covered  with  hair,  and  require  breaking  and  soften- 
ing, which  is  done  by  soaking  them  for  several  days  in 
water,  treading  them  under  feet,  rinsing  and  scraping 
them  on  the  flesh  side  to  produce  evenness.  They  are 
then  made  to  pass  through  three  old  lime-pits,  and  after 
the  hair  is  removed,  through  a  fresh  pit,  the  same  pre- 
cautions being  observed,  throughout,  as  in  the  treatment 
of  calf-skins.  This  process  is  continued  until  the  hair 
can  be  easily  detached,  which  generally  requires  about  a 
month,  and  the  skins  are  then  scraped  on  the  beam,  re- 
immersed  in  lime-milk  for  two  days,  and  again  fleshed 
with  the  scraping-knife. 

Goat-skins  being  of  a  dry  nature,  require  more  rinsing 
than  others,  and  the  operation  must  be  frequently  re- 
peated many  times  in  running  water. 

The  unhaired  skins  are  then  "bated"  with  pigeon's, 
chicken's,  or  dog's  dung,  to  remove  excess  of  lime. 
Fermented  bran-water  is  sometimes  used  as  the  bate. 
24 


362  TANNING  OF  GOAT  AND  Sfl^EP  SKINS. 


After  being  again  scraped^  the  skins  are  sewed  into  bag 
form  with  the  grain  side  outwards,  and  partly  filled 
through  a  funnel  with  a  strong  decoction  of  sumach ;  they 
are  inflated  by  the  breath,  tightly  closed,  and  thrown 
into  a  vat  (Fig.  114)  containing  a  shallow  depth  of  weak 


Fig.  114. 


liquor  of  sumach,  and  therein  made  to  float  about  by 
means  of  constant  agitation,  so  as  to  insure  the  uniform 
action  of  the  tan-liquor  throughout  the  surface  of  the 
skin.  After  a  few  hours,  the  bags  are  taken  out,  and 
piled  upon  each  other  so  as  to  promote  by  pressure  a 
thorough  penetration  of  the  liquor  through  the  pores  of 
the  skin,  and  consequent  chemical  combination.  This 
process  is  repeated  with  new  liquor,  and  the  bags  are 
then  unstitched,  rinsed,  and  scraped  on  the  beam,  and 
suspended  in  the  drying-loft.  These  "crust"  skins,  as 
they  are  termed  when  in  this  latter  condition,  are  moist- 
ened, rubbed  out  smooth  with  a  copper  tool  upon  a  slop- 
ing board,  and  hung  up  to  dry,  previous  to  undergoing 
the  process  of  coloring.  This  method  tans  the  goat- 
skins in  one  day. 

Another  plan  is  to  steep  the  skins  for  several  days  in 
a  fermenting  mixture  of  bran-water,  scrape  them  on  the 
beam,  and  soak  and  rinse  them  in  clean  water.  After 


TANNING  OF  GOAT  AND  SHEEP  SKINS. 


363 


being  limed  in  the  usual  manner,  they  are  worked  or 
rubbed  over  with  a  tool  of  hard  schist,  to  press  out  the 
lime,  smooth  down  unevenness,  and  soften  the  grain,  and 
are  then  fulled  by  agitation  in  a  revolving  cask,  lined 
within  with  pegs,  and  containing  water. 

The  tanning  is  then  effected  in  the  manner  before 
mentioned,  two  pounds  of  Sicilian  sumach  being  required 
for  each  skin.  In  France,  the  tanning  is  accomplished 
very  much  in  the  same  manner  as  by  the  fulling  above 
described ;  the  skins  and  tan-liquor  being  placed  together 
in  a  churn-like  cask,  and  the  chemical  combination  pro- 
moted by  causing  it  to  revolve  upon  a  horizontal  axis. 

Imitation  Morocco. — This  leather  is  prepared  from 
sheep'SkiiiSy  in  the  same  manner  as  true  Morocco;  except 
that,  after  being  stripped  of  wool,  they  must  be  subjected 
to  powerful  hydrostatic  pressure  for  the  expulsion  of  olea- 
ginous matter,  which,  being  contained  in  large  amount, 
would  otherwise  seriously  interfere  with  the  tanning. 

They  are  limed  in  pits  containing  33  pounds  of  lime 
for  every  dozen  skins,  and  are  allowed  to  remain  from 
three  weeks  to  a  month.  They  are  then  deprived  of 
hair,  are  resteeped  in  the  pits  for  five  or  six  days,  rinsed, 
beaten  in  tubs,  and,  when  perfectly  clean,  deposited  in 
ooze  for  a  month. 

When  sheep-skins  are  tanned  for  common  leather,  oak- 
bark  is  used  instead  of  sumach. 

Morocco  is  classified  in  commerce  under  the  head  of 
fancy  leathers,  because  it  always  reaches  market  with  a 
highly  finished  and  colored  surface  on  the  grain  side. 

The  color  is  imparted  in  the  same  manner  as  cloth  is 
dyed — by  means  of  the  chemical  combination  of  a  pig- 
ment with  a  mordant. 

Some  tanners  dye  the  skins  when  they  reach  the  state 
preparatory  to  going  into  the  tan-liquor,  by  sewing  them 


364 


TANNING  OF  GOAT  AND  SHEEP  SKINS. 


together  edgewise,  with  the  grain  outwards,  then  mor- 
danting, and  afterwards  giving  them  two  immersions,  of 
a  half  hour  each,  in  the  dve-bath. 

The  most  common  method,  however,  is  to  take  the 
tanned  skins  as  they  come  from  the  drying-loft,  place 
two  together,  and  then  rub  them  over  exteriorly  with  a 
brush  containing  the  mordant  solution,  and  afterwards 
to  apply  the  dye  liquor  in  the  same  manner.  When  the 
dyeing  is  finished,  they  are  to  be  rinsed,  drained,  spread 
out,  sponged  with  oil  to  preserve  their  flexibility,  and 
then  sent  to  the  curriers'  shop  to  be  finished. 

Black. — This  color  is  imparted  by  the  application  of 
a  solution  of  red  acetate  of  iron;  crimson^  by  a  mordant 
of  alum  or  tin  salt,  and  decoction  of  cochineal;  puce,  by 
mordant  of  alum  and  decoction  of  logwood;  hlue,  by  a 
solution  of  sulphate  of  Indigo;  olive,  by  a  weak  solution 
of  copperas,  as  mordant,  and  decoction  of  barberry  con- 
taining a  little  of  the  blue  bath,  as  coloring  liquor;  violet, 
by  the  consecutive  application  of  decoction  of  cochineal 
and  weak  Indigo  bath. 

Shiver. — This  kind  of  leather  is  made  from  sheep- 
skins split  in  two,  while  in  the  state  of  pelt,  by  machi- 
nery. It  is  tanned  by  sumach  in  vats,  being  spread  out, 
instead  of  sewn  into  bag  form,  as  from  its  lesser  thick- 
ness it  is  more  readily  impregnated  with  the  tan  material. 

The  extreme  thinness  of  a  sheep-skin  renders  neces- 
sary a  peculiar  apparatus  and  nice  manipulation  for  its 
bisection.  The  splitting  machine  used  at  the  Beving- 
tons,  is  shown  in  Fig.  115,  which  also  represents  a  skin 
undergoing  the  process  of  being  split.  A  double  advan- 
tage is  derived  from  this  manipulation,  one  skin  being 
made  into  two  portions,  which  are  then  respectively 
adapted  to  uses  for  which  the  original  skin,  on  account 
of  its  thickness,  was  not  suited.    The  vibrating  knife, 


TANNING  OF  GOAT  AND  SHEEP  SKINS. 


365 


and  rollers,  may  be  so  arranged  as  to  give  an  equal  thick- 
ness to  both  sections  of  the  skin,  or  a  greater  thickness 
to  one  side  than  to  the  other,  as  may  be  desired.  The 
knife  cuts  slowly,  but  completes  the  section  in  about  two 
minutes. 


Fig.  115. 


This  kind  of  leather  is  used  for  hat-linings,  pocket- 
books,  box-covers,  and  like  purposes. 

Roan  is  sheep-skin  Morocco  tanned  with  sumach, 
but  wanting  the  grained  appearance  of  true  Morocco, 
which  is  imparted  by  the  grooved  roller  in  the  finishing. 


CHAPTER  XXVIII. 
TANNING  OF  HORSE-HIDES. 

Previous  to  1790,  the  manufacture  of  good  leather 
from  horse-hides  was  considered  so  problematical,  that 
the  duty  upon  them,  in  France,  did  not  exceed  the  half 
of  that  levelled  upon  neat  hides.  They  were  seldom 
seen  in  tanneries,  and  it  was  impossible  to  pass  them  off 
upon  shoemakers,  as  the  long  necks,  the  unevenness  of 
the  mane  portions,  and  deep  creases,  made  their  charac- 
ter manifest.  At  the  present  day,  however,  they  are 
largely  converted  into  leather;  and  experience  has 
proved,  that  they  make  excellent  material  for  uppers, 
and  the  legs  of  boots. 

Horse-hides  are  limed  in  precisely  the  same  way  as 
calf-skins,  but,  on  account  of  their  greater  thickness,  they 
require  a  longer  exposure  in  the  tan-pits,  eight  months 
being  usually  necessary  for  this  purpose. 

According  to  Dumas,  "horse-hides  are  tanned  with 
great  ease,  and  excellent  leather  can  be  made  from  them 
in  fifty  days,  if  prepared  in  the  following  manner,  which 
is  that  adopted  by  Reulos  and  Budin,  tanners  who  have 
devoted  their  attention  to  this  branch  of  the  business. 
The  skins  are  soaked  for  a  night,  and  then  passed  suc- 
cessively through  three  lime-pits,  remaining  one  day  in 
each,  the  fresh  pit  being  charged  in  the  proportion  of  20 
bushels  of  lime  for  140  skins.    Having  been  taken  out 


TANNING  OF  HORSE-HIDES. 


367 


and  thoroughly  washed  in  running  water,  they  are 
worked  in  the  usual  way  upon  the  beam,  and  then 
passed  through  the  vats,  remaining  six,  eight,  and  in 
winter,  ten  days  in  the  first  one.  During  this  part  of 
the  proceeding,  they  are  taken  out  and  replaced  from 
time  to  time ;  as  often  as  eight  or  ten  times  daily,  for  the 
first  few  days.  The  liquid  of  the  first  vat  should  indi- 
cate a  density  of  °0.7,  by  Baume  s  areometer.  That  of 
the  second  vat  should  be  at  °0.9,  and  while  in  this,  the 
skins  should  be  taken  out  only  once  a  day.  After  nine 
or  ten  days,  they  are  removed  to  the  third  liquid,  which 
has  a  density  of  °1.2,  and  are  allowed  to  remain  in  it  about 
the  same  length  of  time,  and  are  finally  kept  for  twelve 
or  fourteen  days  in  the  last  vat,  at  2°  Baume.  During 
this  last  period,  two  baskets  of  fresh  tan,  weighing  55 
pounds,  should  be  daily  thrown  into  each  vat. 

"After  removal  from  the  last  vat,  the  skins  are 
thoroughly  tanned.  They  are  then  rubbed  upon  marble 
tables,  first  on  the  flesh,  then  on  the  hair  sides,  half- 
dried  upon  hooks  attached  to  the  ceiling  of  the  drying- 
room,  and  sent  to  the  currier  in  a  slightly  moist  state. 

"A  horse-hide  weighing  22  pounds  loses  6 J  pounds  in 
undergoing  cleaning,  but  gains  8^  pounds  in  the  tanning. 
This  method  of  tanning  is  very  simple,  although  requir- 
ing all  the  attention  and  care  of  the  workmen,  and  differs 
from  that  of  other  skins,  at  least  in  the  establishment 
referred  to,  in  their  not  being  placed  at  all  in  pits,  and 
in  being  subjected  to  the  action  of  tannin  while  floating 
in  liquid." 


CHAPTER  XXIX. 


BUCK,  WOLF,  DOa,  AND  OTHER  SKINS. 

The  skins  of  the  buck,  the  wolf,  the  elk,  the  dog,  and 
other  animals,  are  equally  susceptible  of  tanning  as  those 
of  the  goat  and  sheep.  Those  of  the  lamb,  the  kid,  the 
cat,  the  rabbit,  and  hare  do  not  require  exposure  to  as 
strong  infusions,  nor  for  so  great  a  length  of  time,  as 
sheep-skins,  while  those  of  the  hog,  the  wild  boar,  and 
bear  are  prepared  exactly  like  them.  When  these  skins 
are  fresh,  and  when  it  is  intended  to  preserve  the  hair 
or  fur,  the  time  may  be  considerably  abridged. 

HUMAN  SKINS. 

Human  skins  can  be  tanned  like  others.  They  have 
more  body  than  cow-skins,  and,  unlike  them,  are  thickest 
upon  the  abdomen.  Those  who  have  experimented  upon 
this  most  disagreeable  subject,  assert  that  they  require  a 
greater  number  of  limings  and  of  exposures  to  the  infu- 
sions of  bark,  and  that  they  swell  up  a  great  deal  under 
these  operations.  A  tanned  human  skin  is  exhibited  in 
the  Museum  of  Natural  History  at  Versailles.  The  skin 
of  General  Morland  was  exhibited  some  time  since  in 
the  Museum  of  the  Faculty  of  Medicine  of  Paris,  and 
we  have  seen  a  wig  exhibited  by  the  brothers  Norman- 
din,  hairdressers,  which  consisted  of  a  tanned  human 
scalp  with  the  hair  left  on. 


CHAPTER  XXX. 


BUFFALO,  OR  "GRECIAN  LEATHER/^ 

This  leather  is  made  of  buffalo-skins,  and  differs  from 
other  kinds  in  being  tanned  with  myrtle-leaves  instead 
of  oak-bark. 

These  skins,  which  are  always  brought  to  the  tanner 
in  a  dry  state,  are  soaked  in  water  for  five  or  six  days 
in  order  to  soften  them,  and  are  then  deposited  in  an  old 
lime-pit,  and  there  allowed  to  remain  until  the  hair  comes 
off  with  ease,  which  usually  happens  at  the  end  of  eight 
or  ten  days.  During  the  liming,  they  should  be  taken 
out  occasionally,  stacked  for  short  intervals,  and  replaced 
in  the  vats.  When  the  hair  is  just  ready  to  come  off 
without  difficulty,  they  are  scraped  upon  the  beam. 

They  are  next  soaked  in  water  for  two  days;  then 
worked  upon  the  beam  with  a  fleshing-knife,  and  rinsed 
three  or  four  times,  which  should  be  sufficient  to  make 
them  supple  and  to  remove  all  the  lime. 

The  skins  are  then  ready  to  receive  the  first  coloring. 
For  this  purpose,  they  are  placed  upon  each  other  in 
large  vats,  are  covered  over  with  myrtle-leaves,  and,  to 
complete  their  preparation,  the  vats  are  then  filled  with 
a  boiling  decoction  of  powdered  myrtle-leaves. 

After  the  skins  have  been  moved  about  in  this  liquid, 
which  should  always  be  in  sufficient  quantity  to  cover 
them  perfectly,  they  are  taken  out  and  sewed  up  as  other 


370 


BUFFALO^  OR  GRECIAN  LEATHER. 


skins  are  in  processes  already  referred  to.  They  are 
then  filled  up  with  the  leaves  and  fluid  in  which  they 
had  been  immersed,  and  again  replaced  in  the  vat,  which 
is  supplied  with  a  similar  but  fresh  mixture.  This  mix- 
ture must  be  renewed  every  day  if  it  is  desired  to  impart 
a  fine  color  to  the  skins.  To  complete  the  process,  it 
must  be  continued  for  ten  or  twenty  days,  the  skins 
being  frequently  stirred  and  moved  about  in  the  liquid. 
Some  tanners,  however,  only  stir  them  about  two  or 
three  times  daily,  and  once  a  day  throw  into  the  vat  a 
boiler-full  of  hot  myrtle  decoction. 

The  skins,  being  ready  for  the  vats,  are  ripped  up 
and  torn  through  from  tail  to  head.  The  bottom  of 
the  pit  being  bedded  with  powder,  the  skins  are  placed 
upon  it  with  the  hair  side  up,  and  are  then  covered  with 
a  moistened  layer  of  myrtle  leaves,  over  which  skins  are 
placed  as  before,  and  so  on  until  the  pit  is  full.  The 
skins  are  left  in  this  state  for  three  months,  and,  all  the 
precautions  usual  in  common  tanning  having  been  taken, 
are  then  removed,  well  cleaned  in  water,  and  again 
stratified  in  the  same  way  with  myrtle-leaves  for  three 
months  longer.  This  process  is  repeated  four  times 
more  in  the  same  manner,  until,  at  the  expiration  of  a 
year  and  a  half,  they  are  taken  out  and  dried  like  other 
skins.  Some  tanners  keep  these  skins  in  the  pits  for  at 
least  three  years,  but  this  length  of  exposure  is  not  re- 
garded as  at  all  necessary. 

When  nearly  dry,  the  weak  parts  of  the  bellies  are 
cut  out,  and  all  the  wrinkles  in  the  skins  are  flattened 
by  means  of  a  mallet  or  a  smoothing-iron.  They  are 
then  entirely  dried  by  exposure  to  the  open  air,  and 
greased  upon  both  sides.  In  order  that  the  fatty  matter 
may  penetrate  them  perfectly,  they  are  flamed  by  being 
passed  over  a  charcoal  fire  in  every  direction,  until 


BUFFALO,  OR  GRECIAN  LEATHER. 


371 


thoroughly  warmed  throughout;  and,  when  it  is  evident 
that  they  will  absorb  no  more,  are  once  more  warmed 
and  then  piled  up  and  covered  with  planks,  which  are 
pressed  down  with  large  stones  or  heavy  weights. 

The  next  day,  they  are  taken  down  and  dried 
thoroughly  by  exposure  to  the  open  air,  when  they  will 
be  found  to  have  acquired  the  necessary  whiteness  and 
firmness. 


CHAPTER  XXXI. 


RUSSIA  LEATHER. 

The  Russians  have  long  been  in  possession  of  a  method 
of  making  a  variety  of  fancy  red-colored  leather,  called 
by  them  juden.  This  article  has  a  peculiarly  agreea- 
ble- and  characteristic  odor,  is  not  subject  to  mould  when 
exposed  in  damp  situations,  and  is  proof  against  the 
attacks  of  insects,  even  expelling  them  from  the  vicinity 
of  its  odor. 

A  description  of  this  process  has  been  published  by 
Pallas  and  by  Fischerstroem,  and  a  manufactory  of 
Russia  leather  was  established  at  St.  Germain,  more 
than  sixty  years  ago,  under  the  auspices  of  M.  Teybert; 
but  it  did  not  prove  as  successful  as  was  expected.  Since 
then,  the  manufacture  has  been  more  generally  intro- 
duced into  France.  The  following  account  of  the  process 
is  chiefly  taken  from  the  prize  work  on  the  subject  by 
Grouvelle  and  Duval-Duval,  and  from  the  Technological 
Dictionary  of  M.  Pay  en ;  but  all  the  published  descriptions 
are  more  or  less  imperfect,  and  it  is  probable  that,  even 
at  the  present  day,  the  particulars  of  the  method  em- 
ployed in  Russia  are  not  thoroughly  known  out  of  that 
country. 

Russia  leather  consists  of  calf,  sheep,  and  goat  skins, 
dyed  generally  of  a  red  color,  cylindered,  and  impregnated 
with  a  purified  empyreumatic  oil  obtained  from  birch- 


RUSSIA  LEATHER. 


373 


bark.  For  this  purpose,  the  whitest  and  most  perfect 
skins  are  selected.  These  are  deprived  of  hair  by  steep- 
ing them  in  a  mixture  of  ash-lye  and  quicklime,  made 
too  weak  to  act  upon  the  animal  fibres.  They  are  then 
rinsed,  fulled  for  a  longer  or  shorter  time  according  to 
their  nature,  and  fermented  in  a  proper  steep,  after  hav- 
ing been  washed  in  hot  water.  They  are  taken  out  at 
the  end  of  eight  days,  fulled  again,  and  steeped  a  second 
time,  if  this  be  necessary  to  open  their  pores,  and  then 
cleaned  with  the  flesh-knife  on  both  the  flesh  and  grain 
sides. 

A  paste  is  then  made,  consisting  of  38  pounds  of  rye- 
flour  for  200  skins,  and  fermented  with  leaven;  and 
the  dough  is  worked  up  with  a  sufficient  quantity  of 
water  to  form  a  bath  for  the  skins,  in  which  they  are 
soaked  for  forty-eight  hours,  then  transferred  to  small 
pits,  and,  after  remaining  therein  for  fifteen  days,  are 
well  washed  in  the  river.  This  preliminary  operation 
serves  to  prepare  the  skins  for  their  uniform  and  com- 
plete combination  with  tannin  and  extractive  matter. 
A  decoction  of  willow-bark  (salix  ci7ierea  and  salix  caprea) 
is  then  made,  and,  when  its  temperature  is  sufficiently 
lowered  to  prevent  it  from  injuring  the  animal  fibres, 
the  skins  are  immersed  in  it,  and  handled  and  worked 
for  a  half  hour.  This  manipulation  is  repeated  twice 
daily  during  a  week ;  after  which,  a  fresh  decoction  is 
prepared,  and  the  skins  are  subjected  to  the  same  treat- 
ment in  it  for  another  week.  After  this,  they  are  ex- 
posed to  the  air  to  dry,  and  are  then  ready  to  be  dyed 
and  dressed  with  the  oil. 

Another  method  of  preparing  the  skins  for  the  chief 
operation  is  given  by  Dessables. 

The  whitest  and  most  perfect  skins  being  selected,  are 
soaked  in  water,  scraped  upon  the  beam,  fulled,  worked 


374 


RUSSIA  LEATHER. 


with  the  pommel,  and  then  oiled  upon  the  hair  side  with 
pure  fish  oil,  and  upon  the  flesh  with  a  mixture  of  oil 
and  train  oil  scourings.  When  dry,  they  are  again  pom- 
melled, washed  over  upon  the  hair  side  with  a  solution 
of  alum,  and  then  pressed  under  the  cylinder.  This 
cylinder,  by  which  the  diamond-shaped  grain  is  given  to 
Russia  leather,  is  made  of  steel,  about  twelve  and  a  half 
inches  long,  and  three  inches  in  diameter,  and  is  covered 
with  a  number  of  close  parallel  threads,  or  grooves,  like 
those  of  a  screw,  but  cut  perpendicular  to  its  axis,  and 
not  spirally.  The  cylinder  is  filled  with  stones  weighing 
from  200  to  340  pounds.  It  is  moved  in  two  directions 
upon  a  wooden  bench,  or  support,  by  means  of  a  cord 
passing  around  a  wooden  roller  with  a  handle.  This 
cord  passes  also  over  two  cylinders  attached  to  the  floor, 
and  a  fourth  one  upon  the  end  of  the  bench.  The 
cylinder  having  the  handle  upon  its  axle,  is  divided  into 
two  different  parts,  over  which  the  two  extremities  of 
the  cord  pass  in  different  directions,  so  that  two  opposite 
movements  can  be  given  to  the  cylinder  by  one  handle. 

The  cylinder  is  sustained  and  directed  by  iron  bars 
placed  along  the  bench  upon  which  it  rolls.  The  skin 
which  is  to  be  grained  is  placed  below  it,  lengthwise, 
upon  the  bench,  and  longitudinal  grooves  are  impressed 
upon  its  surface  by  the  track  of  the  cylinder.  The  skin 
is  then  removed  and  again  placed  upon  the  bench,  either 
crosswise  or  at  an  angle,  according  as  it  is  intended  to 
give  it  a  square  or  a  diamond-shaped  grain. 

When  properly  grained,  a  second  coat  of  alum-water 
is  applied,  and  when  nearly  dry,  the  Russian  oil  is 
spread  over  the  hair  side,  and  the  red  or  the  black  color 
is  given.  The  skin  is  then  repeatedly  exposed  for  a 
short  time  to  the  direct  rays  of  a  hot  sun,  until  the 
color  has  sufficiently  penetrated  its  substance,  when  it 


RUSSIA  LEATHER. 


375 


is  fulled,  pommelled,  sleeked  with  the  round-knife,  upon 
the  beam,  and  finally  well  rubbed  upon  the  hair  side 
with  a  hard  brush. 

The  chief  characteristic  of  the  preparation  of  Russia 
leather,  is  its  impregnation  with  the  birch-bark  oil,  the 
mode  of  manufacturing  which  is  still,  in  a  measure,  kept 
secret.  In  order  that  the  oil  should  penetrate  the 
leather  properly,  the  latter  must  not  be  either  too  moist 
or  too  dry,  but  should  contain  just  sufficient  water  to 
enable  the  oil  to  be  spread  equally  over  the  surface,  and 
to  be  absorbed  in  proportion  as  the  moisture  gradually 
evaporates.  Thus  prepared,  the  leather  retains  the  cha- 
racteristic odor  for  a  long  time.  Great  care  should  be 
taken  not  to  apply  too  much  of  the  oil,  for  fear  of  its 
passing  through  and  staining  the  grain  side.  From 
twelve  ounces  to  a  pound,  generally  suffice  for  fully  im- 
pregnating a  large  cow-skin.  In  the  case  of  leather  not 
dyed,  or  of  Morocco  to  which  it  may  be  desired  to  im- 
part the  odor,  only  a  very  small  portion  should  be  applied 
to  the  flesh  side. 

The  composition  of  the  red  color  with  which  Russia 
leather  is  commonly  stained,  has  not  been  accurately 
ascertained.  It  usually  contains  Brazil  wood,  alum,  and 
some  other  ingredients.  It  is  not  very  durable,  and  does 
not  resist  the  action  of  boiling  water  or  of  potassa, 
though  it  generally  remains  unaltered  in  the  air.  Other 
dyes  of  better  quality  are  sometimes  used,  which  enhance 
the  price  of  the  leather.  The  black  Russia  leather  is 
prepared  in  the  same  way  as  the  other,  and  is  stained 
by  the  repeated  application  of  the  acetate  of  iron. 

Much  attention  has  been  bestowed  upon  the  manu- 
facture of  the  empyreumatic  oil  of  birch-bark,  and  quite 
a  number  of  different  modes  of  preparing  it  have  been 


376 


RUSSIA  LEATHER. 


described.  The  following  is  that  given  by  Fischerstroem 
as  the  one  practised  in  Russia. 

The  whitish  membraneous  epidermis  of  the  birch, 
carefully  separated  from  all  woody  matter,  is  introduced 
into  an  iron  boiler,  which,  when  entirely  full,  is  covered 
tightly  with  a  vaulted  iron  lid,  from  the  centre  of  which 
issues  an  iron  pipe.  Another  boiler,  into  which  this  tube 
enters  without  touching  its  bottom,  is  placed  over  the 
other,  and  the  edges  are  bolted  together  and  tightly 
luted.  They  are  then  inverted,  so  that  the  one  contain- 
ing the  bark  is  uppermost.  The  lower  half  of  this  ap- 
paratus is  sunk  in  the  earth,  the  surface  of  the  upper 
boiler  is  covered  over  with  a  lute,  composed  of  clay  and 
sand,  and  then  surrounded  with  a  wood  fire  and  exposed 
to  a  red  heat  until  the  completion  of  the  distillation. 
As  soon  as  the  boilers  are  cold,  they  are  disconnected. 
A  light  powder  of  charcoal  is  found  in  the  upper  one, 
and  in  the  under  one,  which  served  as  a  receiver,  a  brown, 
oily,  odoriferous,  empyreumatic  liquid,  mixed  with  tar 
and  pyroligneous  acid.  This  oil  is  separated  from  the 
other  substances,  and  preserved  in  tightly  stopped  vessels. 

In  another  method  of  preparing  this  oil,  the  dry  birch- 
bark  is  introduced  into  a  large  earthen  pot,  having  a 
hole  in  the  bottom.  When  the  pit  is  full,  the  bark  is 
set  fire  to ;  another  similar  earthen  pot,  with  a  hole  for 
the  escape  of  smoke,  is  inverted  over  the  first  one,  and 
the  latter  is  placed  upon  a  bucket,  into  which  the  tar 
and  oily  matters  drop  as  they  are  formed.  When  the 
process  is  conducted  in  spring,  some  manufacturers  mix 
the  young  branches  of  the  birch,  covered  with  buds, 
with  the  bark.  This  arrangement  facilitates  the  separa- 
tion of  the  oil,  which,  when  thus  prepared,  is  also  of  a 
lighter  color,  from  the  smaller  quantity  of  soot  contained 
in  it. 


RUSSIA  LEATHER. 


377 


The  oil  is  prepared  in  France,  bj  distilling  tlie  birch- 
bark  in  copper  stills,  and  condensing  the  products  by 
means  of  a  worm  kept  cold  by  water.  About  sixty 
per  cent,  of  the  weight  of  the  bark  may  thus  be  ex- 
tracted. The  oil  obtained  in  this  way,  is  highly  colored 
and  not  very  abundant,  but  may  be  still  rectified  by  re- 
distillation, so  as  to  be  almost  perfectly  colorless.  When 
thus  purified,  it  is  better  adapted  than  the  original  pro- 
duct, for  the  oiling  of  very  fine  or  white  leather,  which 
it  is  important  not  to  stain ;  but  its  preparation  is  costly 
to  the  manufacturer,  on  account  of  the  loss  of  material, 
and  the  small  quantity  of  it  obtained. 

Another  method  of  distilling  the  oil,  proposed  by 
Payen,  is  a  very  simple  one,  which  yielded  to  him  a 
large  quantity  of  a  light-colored  product.  A  hole  is 
made  in  the  bottom  of  an  earthen  furnace  A,  Fig.  116, 


Fig.  116. 


large  enough  to  receive  the  neck  of  a  matrass  M,  The 
furnace  is  supported  by  two  bricks  placed  upon  the 
plank,  which  is  also  perforated  so  as  to  admit  of  the 
25 


378 


EUSSIA  LEATHER. 


passage  of  the  neck  of  the  matrass,  and  which  rests 
upon  the  trestles  (7.  After  having  filled  the  matrass  to 
its  utmost  capacity  with  birch-bark  epidermis,  it  is  in- 
verted and  passed  through  the  furnace  and  the  board. 
The  neck  is  then  luted  and  placed  in  the  position  seen  in 
the  figure,  being  supported  by  sand  thrown  into  the  bottom 
of  the  furnace  as  high  as  F\  and  in  order  to  expose 
the  body  of  the  matrass  to  a  uniform  heat,  it  is  pro- 
tected by  inverting  over  it  an  earthen  hemispherical 
cupel,  or  crucible.  Around  this  burning  coals  are  placed, 
and  the  fire  is  kept  up  through  two  lateral  openings  i), 
i^,  the  dome  /,  Z,  being  placed  upon  the  furnace-top. 
Condensed  water  first  trickles  from  the  mouth  of  the 
matrass  into  a  vessel  placed  beneath,  and  this  is  suc- 
ceeded by  drops,  and  then  by  a  constant  stream  of  an 
amber-colored  oil.  After  a  time  this  ceases,  and  it  is 
necessary  to  apply  heat  lower  down  to  the  neck  of  the 
matrass,  so  as  to  cause  the  discharge  of  the  last  portions 
of  oil  and  tarry  matters  which  have  condensed  in  it. 
The  products  of  the  distillation  of  1000  parts  were: — 

1.  A  fluid,  brown,  oily  matter,  very  odoriferous, 

and  soluble  in  ether        .       .       .  .700 

2.  Thick,  dark-brown,  tarry  fluid,  containing  a 

little  oil   50 

3.  Water,  acidulated  by  pyroligneous  acid        .  100 

4.  Light  spongy  charcoal,  left  in  the  matrass    .  125 

5.  Loss  by  the  escape  of  gaseous  substances     .  25 

This  oil  may  be  more  readily  prepared  by  distilling 
the  bark  in  cylinders  of  iron,  placed  horizontally  in  the 
furnace  similarly  to  gas  retorts. 

Chevreul,  and  after  him  Payen  and  Chevalier,  have 
investigated  the  chemical  nature  of  the  odoriferous  sub- 
stance to  which  the  properties  of  the  oil  of  birch-bark 


RUSSIA  LEATHER. 


379 


are  owing,  and  to  which  the  name  of  hetuline  has  been 
given.  The  latter  chemist  found  that  the  epidermis  of 
the  bark  contains  two  or  three  per  cent,  of  this  proxi- 
mate principle,  which  is  a  white  pulverulent  substance, 
soluble  in  alcohol,  condensing  when  volatilized  into  crys- 
talline needles,  and  giving  off,  when  thrown  upon  burn- 
ing coals,  a  thick  white  vapor,  similar  to  that  of  Eussia 
leather  but  more  agreeable. 

The  leather  manufactured  in  Eussia,  and  elsewhere  in 
imitation  of  it,  is  applied  to  various  useful  and  orna- 
mental purposes;  portfolios,  surgical  instrument  cases, 
pocket,  blank,  and  memorandum  books,  souvenirs,  &c., 
being  covered  with  it.  These  articles,  and  books  bound 
with  it,  retain  the  characteristic  odor  for  a  long  time, 
and  are  protected  by  it  from  the  attacks  of  mould  or  of 
insects. 

We  conclude  this  subject  by  extracts  from  a  memoir 
by  the  Count  de  Kartsoff,  on  the  various  methods  of 
tanning  employed  in  Eussia. 

The  dried  skins  are  softened  by  soaking  in  water  for 
five  or  six  days  in  summer,  and  ten  or  twelve  in  winter; 
and,  after  being  well  cleaned,  are  deprived  of  hair  by 
steeping  in  milk  of  lime — 185  pounds  of  lime  being 
mixed  with  the  water,  in  a  vat  eight  feet  in  diameter,  and 
seven  feet  three  inches  in  height.  The  skins  are  fre- 
quently examined,  and,  when  the  epidermis  and  hairs 
^  give'  readily,  they  are  removed  upon  the  horse  by  the 
use  of  a  dull  two-handled  knife,  after  which  the  skins 
are  carefully  fleshed. 

"  Strong  hides  are  not  freed  from  hair  in  lime-vats,  but 
are  exposed  in  a  sweating-room,  piled  up  upon  each 
other,  and  sprinkled  over  with  salt  to  prevent  decompo- 
sition; and  bran-baths  are  used  for  the  same  purpose  in 
the  treatment  of  certain  kinds  of  thin  and  delicate  skins. 


380 


RUSSIA  LEATHER. 


"  The  skins,  after  being  limed,  are  well  soaked^  washed, 
beaten  out  with  the  feet,  and  rinsed  in  warm  water  until 
the  last  portions  of  lime  have  been  removed  from  them ; 
and  they  are  then  raised  by  steeping  for  forty-eight  hours 
or  more  in  a  vat  of  the  dimensions  before  given,  contain- 
ing a  fermented  mixture  of  warm  water  with  1100  pounds 
of  rye  meal,  or  450  pounds  of  oat  meal,  6  pounds  of  salt, 
and  a  sufficiency  of  leaven.  Being  thus  prepared  for 
the  tanning,  they  are  steeped  for  a  time  in  a  weak  infu- 
sion of  oak  or  willow  bark,  the  latter  being  preferred,  and 
are  then  stratified  in  a  vat  with  layers  of  coarse  bark ; 
the  vat  being  filled  up  with  the  tanning  infusion  first 
used,  and  its  contents  being  pressed  down  with  planks 
heavily  weighted  with  stones.  The  skins  are  left  in  this 
vat  for  a  time  varying  from  fifteen  to  twenty-eight  days, 
after  which  they  are  removed,  and  again  stratified  with 
fresh  bark.  This  operation  is  repeated  from  three  to 
six  times,  according  to  the  nature  and  quality  of  the 
skins — the  thinnest  kinds  only  requiring  two  changes. 
The  stifihess  acquired  by  the  leather  in  tanning  is  then 
corrected  by  soaking  them  for  a  day  or  two  in  a  thin 
paste,  composed,  for  every  150  skins  of  ordinary  size,  of 
130  pounds  of  oatmeal  and  9  pounds  of  salt,  mixed  with 
warm  water. 

The  leather  is  then  well  washed,  rinsed,  and  drained, 
and,  while  in  a  partially  moist  state,  is  placed  upon  a 
large  table,  with  the  flesh  side  up,  and  coated  with  oil. 
This  is  composed  of  a  mixture  of  the  oil  obtained  from 
sea-calves  (which  abound  in  the  Caspian  Sea),  and  of  the 
pure  oil  or  tar  of  birch-bark,  in  various  proportions,  ac- 
cording to  the  nature  and  quality  of  the  leather;  one 
part  of  the  latter  to  two  of  the  former  being  generally 
used.  The  workman  spreads  the  mixture  with  his  hand 
evenly  and  uniformly  over  the  surface,  and  the  perfec- 


RUSSIA  LEATHER. 


381 


tion  of  the  operation  depends  upon  the  skill  with  which 
this  is  done.  About  nine  ounces  of  oil  are  applied  to 
each  skin  of  medium  size.  When  oiled,  the  leather  is 
then  stretched  out  upon  cords  in  an  open  shed  until  per- 
fectly dry,  and,  in  the  winter  season,  is  exposed  to  the 
cold  air,  by  which  its  appearance  is  much  improved. 

'^The  Baskirs  and  Kirguises  prepare  their  skins  by 
smoking  in  lieu  of  tanning  them.  They  first  stretch 
them  out,  in  their  green  state,  between  stakes  fixed  in 
the  ground,  and  then  remove  the  hair  by  scraping  them 
with  a  broken  sickle  fixed  in  a  wooden  handle.  They 
then  dig  a  pit  in  the  ground,  proportioned  in  size  to  the 
number  of  skins  to  be  operated  upon,  and  suspend  across 
it  parallel  cords  which  are  attached  to  its  edges.  A 
round  hole  is  then  dug,  five  feet  from  the  edge  of  the  pit, 
and  is  connected  with  it  by  a  subterranean  gutter.  The 
skins  are  hung  upon  the  cords,  the  pit  is  covered  over, 
and  a  fire  of  dry  rotten  wood  is  lighted  in  the  small  hole, 
the  top  of  wdiich  is  then  closed.  The  smoke  passes 
through  the  colmecting  gutter  into  the  pit,  and  the  skins 
are  kept  exposed  to  its  action  for  two  or  three  weeks,  at 
the  end  of  which  time  they  are  found  to  have  acquired 
properties  similar  to  those  of  leather,  and,  above  all,  a 
degree  of  impermeability  which  does  not  exist  in  that 
which  is  tanned." 


CHAPTEE  XXXII. 
RED  SKINS. 


When  the  skins  are  fresh,  they  are  soaked  for  eight 
hours  in  vats  or  in  running  water,  and,  when  dry,  besides 
this  soaking,  are  taken  out  every  day  and  softened  upon 
the  leg.  After  being  sufficiently  soaked,  they  are  de- 
j)osited  in  a  solution,  made  by  boiling  and  stirring  about 
in  water  two  parts  of  wood-ashes  and  one  part  of  fresh 
quicklime,  by  decanting  this  liquid  into  a  vat,  and  dilut- 
ing it  with  a  sufficient  quantity  of  water.  A  grating  is 
placed  above  the  bottom  of  the  vat,  so  that  the  skins 
may  not  come  in  contact  with  the  ashes,  which  sink 
below  the  grating. 

When  the  hair  is  ready  to  be  removed,  which  usually 
happens  in  eight  days,  the  skins  are  taken  out  and 
scraped  with  the  round  knife.  They  are  then  attached 
together,  two  and  two,  hung  on  pegs,  and  exposed  to  a 
stream  of  water,  in  order  to  wash  away  the  ashes  and 
lime.  After  three  days,  they  are  taken  out,  worked  on 
the  hair  side,  hung  up  to  drain,  fleshed,  and  trod  out 
with  the  feet. 

The  smaller  skins  are  now  soaked  during  twentj^-four 
hours  in  a  hole  or  trough,  filled  with  a  mixture  of  dog's- 
dung  and  warm  water.  They  are  then  taken  out, 
cleansed,  and  rinsed,  and  macerated  for  twenty-four 
hours  in  a  bath  made  with  oatmeal  and  malt,  after  which 


RED  SKINS. 


383 


they  are  deposited  in  a  tan-liquor,  in  which  they  remain 
three  days. 

They  are  then  severally  sprinkled  over  with  finely 
powdered  oak-bark,  and  are  piled  up  above  the  grating 
of  the  vat,  which  is  filled  with  a  mixture  of  equal  parts 
of  water  and  of  the  tan-liquor.  The  smaller  ones  remain 
in  this  for  eight  days,  those  of  a  larger  size  being  exposed 
for  a  longer  time. 

After  this  exposure,  they  are  taken  out,  rinsed,  trod 
out,  fleshed,  and  replaced  in  the  vats,  being  each  time 
sprinkled  over  with  powder  as  before.  This  series  of 
operations  is  repeated  four  times,  the  skins  remaining 
for  three  weeks  in  the  vats  the  fourth  time.  When 
properly  tanned,  they  are  stretched,  dried,  and  given  to 
the  currier  to  polish  and  color. 

The  red  color  is  commonly  applied  to  goat-skins,  or 
the  skins  of  calves  under  two  years  of  age,  and  is  made 
of  red  sandal-wood,  while  the  black  is  produced  by  the 
use  of  black  sandal-wood,  1  pound  2  ounces  of  the  wood 
being  required  for  a  large  skin,  and  about  9  ounces  for  a 
small  one.  To  the  mixture  used  to  blacken  one  hundred 
skins,  2  pounds  9  ounces  of  green  vitriol,  or  copperas,  are 
added,  and  an  equal  quantity  of  alum  is  mixed  with  the 
red  dye  for  the  same  number.  The  skins  are  sewed 
around  with  small  stitches,  forming  sacks  which  are 
completely  closed,  with  the  exception  of  the  small  aper- 
ture left  for  the  introduction  of  the  coloring  matter. 
This  is  pou];ed  in  hot,  the  opening  is  sewed  up,  and  the 
bag  is  rolled  about  in  every  direction,  so  that  the  dye 
may  be  brought  in  contact  with  all  parts  of  the  surface. 

When  this  is  accomplished  perfectly,  the  skins  are 
ripped  up,  dried,  and  two  more  coats  of  color  are  applied 
by  converting  the  skin  into  a  kind  of  roller,  and  passing 
it  over  the  coloring  matter.    After  the  color  has  been 


384 


RED  SKINS. 


sufficiently  imparted  to  the  surface,  it  is  daubed  over 
with  birch  tar  or  whale  oil,  and  when  nearly  dry, 
the  lustre  is  given  with  a  finely  grooved  pummel,  or 
grainer,  passed  over  in  both  directions.  The  furrows 
observable  on  the  surface  of  this  leather,  are  made  by 
this  mode  of  working.  When  properly  grained,  it  is 
dried  and  sprinkled  with  hemp-seed  oil,  and  the  last 
polish  is  given  upon  the  horse. 


CHAPTER  XXXIII. 

WALLACHIA  LEATHER. 

This  kind  of  leather  derives  its  title  from  tlie  province 
of  that  name,  and  is  made  by  barley  dressings,  in  a  single 
warm  vat.  After  having  been  softened  in  water,  the 
hides  are  trampled  under  feet,  and  then  worked  on  the 
j3^esh  side  with  the  scraping-knife,  so  as  to  render  them 
supple;  after  which  they  are  rinsed  in  water,  and  hung 
up  to  drain.  Examination  is  then  made,  to  ascertain  if 
the  hair  can  be  easily  detached,  for,  in  summer,  and 
warm  climates,  this  is  effected  without  any  other  prepa- 
ration. When  fresh  skins  are  employed,  fermentation  is 
resorted  to  for  removing  the  hair;  and,  after  the  removal 
of  the  tail,  horns,  and  ears  by  the  knife,  the  skins  are 
salted  without  being  soaked.  The  salting  of  each  large 
hide  consists  in  sprinkling  it  over  with  from  four  to  six 
pounds  of  salt,  alum,  and  saltpetre,  doubling  it  in  the 
centre,  so  that  one-half  is  exactly  folded  over  the  other, 
stacking  it,  and  covering  the  pile  with  straw.  All  be- 
ing thus  arranged,  the  hides  soon  become  heated,  and 
it  is  then  necessary  to  turn  them  once  or  twice  daily,  and 
at  the  same  time  to  change  the  folds,  and  the  sides,  so  as 
to  insure  a  uniform  fermentation  throughout.  As  soon 
as  the  hair  can  be  detached  readily,  the  depilation  is  to 
be  immediately  commenced,  for  any  delays  might  prove 
injurious  to  the  grain  of  the  leather. 


386 


WALLACHIA  LEATHER. 


If  any  unexpected  occurrence  should  prevent  the  im- 
mediate depilation  of  the  hides,  they  are  then  to  be 
soaked  in  water  for  one  or  two  days,  but  not  longer,  for 
fear  of  their  undergoing  incipient  putrefaction.  It  is 
unnecessary  to  say  that  those  hides  should  be  first  re- 
moved, which  yield  their  hair  with  the  greatest  ease. 

This  23rocess  can  be  accomplished  without  the  aid  of 
salt,  in  the  manner  already  described ;  as  a  general  rule, 
the  hair  should  give  with  a  noise,  when  it  is  plucked  out 
with  the  fingers.  The  more  difficult  this  depilation,  the 
better  will  be  the  skin,  since  it  is  thus  proved  that  it  has 
suffered  no  alteration  by  the  heating.  The  parts  denuded 
during  or  previous  to  the  operation,  should  be  moistened 
with  a  solution  of  salt,  so  that  they  may  not  be  over- 
heated before  the  other  portions  are  ready  for  depilation. 

Depilation  can  also  be  effected  by  means  of  stable 
manure.  We  will,  however,  mention  that  the  three 
methods  by  fermentation  are  the  most  objectionable,  as 
the  skins  nearly  always  suffer  more  or  less  from  incipient 
putrefaction.  In  following  even  the  method  which  we 
are  about  to  describe,  it  would  be  much  better  to  employ 
the  exhausted  vats,  or  those  which  we  have  already  re- 
ferred to.  As  soon  as  the  depilation  is  finished,  the 
raising  is  effected  in  the  following  manner : — 

Take  for  seven  skins,  each  averaging  eighty  pounds, 
twenty  pounds  of  wheat  flour,  make  it  into  leaven,  diffuse 
in  water  to  a  pasty  consistence,  and,  to  accelerate  the 
fermentation,  add  besides  a  gill  and  a  half  of  vinegar. 
After  this  leaven  is  made,  which  requires  twenty-four 
hours,  it  must  be  kept  covered  in  a  warm  place  for  three 
or  four  days. 

The  tub  for  six  or  seven  skins,  should  be  five  and  a 
quarter  feet  in  diameter,  and  three  and  a  quarter  feet 
in  height,  and  well  cleansed,  or  free  from  everything  an- 


WALLACHIA  LEATHER. 


387 


tagonistic  to  the  development  of  acid  fermentation. 
Having  been  filled  with  water,  six  or  seven  buckets-full 
are  then  withdrawn,  boiled,  and  a  part  used  for  making 
a  uniform  paste  out  of  ground  barley,  which  must  after- 
w\ards  be  thinned  out  with  cold  water  to  the  consist- 
ence of  syrup.  This  paste  is  then  boiled  till  it  froths, 
during  constant  stirring  with  a  wooden  paddle,  and  when 
it  has  bubbled  or  foamed  three  times,  it  is  to  be  poured 
in  the  tub  destined  for  the  dressing,  and  cooled  by  stir- 
ring w^ith  the  paddle  kept  moving  constantly  in  the  same 
direction.  Its  temperature  should  not  be  insupportable 
to  the  hand.  Six  pounds  of  salt  are  then  to  be  stirred 
in,  the  tub  is  to  be  covered,  and  the  contents  left  for  two 
weeks  to  sour.  It  must,  however,  be  stirred  twice  daily ; 
but  in  order  to  confine  the  heat,  the  cover  should  not 
be  kept  off,  for  that  purpose,  longer  than  is  absolutely 
necessary. 

The  skins  are  then  taken  from  the  rinse-water,  strung 
in  threes  upon  a  rope  thrown  into  the  tub,  and  there  left  for 
four  or  five  days.  But  on  each  day  they  must  be  with- 
drawn twice,  rinsed,  left  to  drain  for  a  minute,  and  put 
back  in  the  tub.  Finally,  when  the  skins  are  well 
broken,  and  the  hair  sides  have  become  sufficiently  soft 
to  retain  the  impression  of  the  finger-nail,  they  are  taken 
out  and  fleshed.  If  portions  of  the  hair  should  still 
adhere,  the  hides  are  spread  upon  the  beam,  or  horse, 
and  are  scraped  with  the  knife  shown  by  Fig.  117. 

Fig.  117. 


After  being  shaved,  they  are  rinsed  in  clean  water,  sus- 
pended, and  left  to  drain  for  twenty-four  hours.  In  the 
mean  time  a  second  leaven,  from  sixteen  pounds  of  meal, 


388 


WALLACHIA  LEATHER. 


is  made  and  fermented  in  the  same  way  as  the  previous 
one. 

The  sour  liquor  is  then  transferred  from  the  vat  of  the 
first  dressing,  and  tlie  clear  supernatant  portion  poured 
into  the  second  tub  wherein  is  to  be  given  the  comple- 
me7it,  or  completion,  which  is,  in  fact,  but  a  repetition  of 
the  preceding  operation.  Six  or  seven  buckets-full  of 
the  clear  sour  water  of  the  tub  are  taken  from  each 
vat,  are  boiled,  and  a  portion  stirred  up  with  about  fifty 
pounds  of  ground  barley,  or  about  eight  pounds  for  each 
skin.  The  residue  of  the  hot  w^ater  is  then  gradually 
added,  the  whole  is  gently  boiled  and  distributed  in  the 
new  dressings,  well  stirred,  and  a  bucket  or  two  taken 
out  and  heated  nearly  to  ebullition.  The  second  leaven 
(made  with  eight  pounds  of  meal)  is  then  distributed  in 
the  tubs;  four  or  six  pounds  of  salt  are  added  to  each, 
and  the  whole  is  ultimately  mixed  by  stirring.  Several 
buckets-full  should  be  taken  out  and  held  in  reserve,  so 
that  it  may  be  ready  for  supplying  any  deficiency  in  the 
quantity  of  the  liquid,  which  should  not  be  greater  than 
eight  inches  in  height.  If  this  method  is  too  tedious, 
it  may  be  simplified  by  making  one  step  of  the  two,  and 
using  at  once  30  pounds  of  leaven,  120  of  barley,  and 
10  of  salt,  for  each  dressing  of  six  hides.  It  must  be 
here  observed  that,  by  the  ordinary  process,  the  tanners 
use  at  one  time  in  their  first  new  dressing,  just  twice 
the  quantity  of  barley  that  would  be  employed  here ; 
and,  moreover,  when  their  first  new  dressing  is  not  suf- 
ficient, they  are  obliged  to  make  a  second,  w^hich  renders 
the  process  more  tedious  and  expensive  than  that  of 
Wallachia.  It  is  also  necessary  to  say  that,  on  the 
addition  of  salt,  the  dressing  must  always  be  well  stirred, 
and  two  or  three  buckets-full  of  the  liquor  drawn  out 
from  each,  and  kept  warm  to  be  poured  into  the  vat,  in 


WALLACHIA  LEATHER. 


389 


order  to  maintain  the  temperature.  Several  other 
buckets-full  are  also  taken  out  and  poured  into  a  re- 
served tub,  so  that  no  more  liquor  may  remain  in  each 
dressing  than  is  sufficient  to  cover  the  skins  subjected 
to  its  action.  Many  tanners  believe  that  it  is  better  to 
make  the  whole  of  the  composition  at  once,  for  inde- 
pendently of  loss  of  time  and  fuel,  it  may  so  happen 
that  the  complement  made  with  the  new  quantity  of 
barley  may  retard  the  progress  of  fermentation^  and 
that  the  liquor  must  then  be  heated  to  a  temperature 
which  would  be  injurious  to  the  skins. 

There  are  various  modes  of  making  the  single  composi- 
tion: 1,  from  barley  or  rye  meal  without  leaven,  pre- 
pared over  night  with  boiling  water :  2,  from  equal  parts 
of  barley,  meal,  and  leaven,  thinned  out  with  water, 
and  heated  nearly  to  ebullition,  just  previous  to  putting 
in  the  skins  :  3,  from  wheat-bran,  in  the  proportion  of 
a  half  bushel  per  hide,  thinned  out  with  hot  water, 
and  after  a  day's  fermentation  mixed  with  a  pound  of 
salt  for  each  skin  :  4,  from  leaven  of  barley  or  rye,  as 
substitutes  for  that  from  wheat^  in  the  proportion  of 
from  six  to  eight  pounds  of  flour  per  hide.  When  the 
leaven  rises,  it  must  be  thinned  out  with  water  of  86°  F., 
and  the  salt  added  just  before  the  skins  are  put  in. 

Barley-dressings. — When  the  fermentation  is  well  esta- 
blished, as  may  be  known  by  the  acidity  of  the  waters, 
the  dressings  are  ripe  and  ready  to  receive  the  skins, 
which  are  then  taken  from  the  hangers,  and  passed  in 
and  out  of  the  liquor  several  times,  so  as  gradually  to 
equalize  the  temperature.  After  this,  they  are  left  upon 
the  cover  of  the  tub  to  drain  for  a  few  minutes.  In  the 
interval,  the  liquor  is  stirred,  the  skins  are  put  back, 
the  tubs  covered,  and  the  heat  of  the  dressings  is  main- 


390 


WALLACHIA  LEATHER. 


tained  with  the  liquor  kept  warm  and  in  reserve.  In 
fifteen  minutes,  the  hides  are  a  second  time  taken  out 
and  left  to  drain  fifteen  minutes,  and  are  then  again  put 
back.  After  a  half  an  hour,  they  are  removed  for  the 
third  time,  left  to  drain  for  a  quarter  of  an  hour,  then 
returned  to  the  tub,  and  again  taken  out  to  drain  for 
twenty  minutes.  The  fifth  time  of  dipping,  they  are 
left  in  the  tub  for  an  hour,  and  allowed  to  drain  for 
thirty  minutes.  Finally,  they  are  taken  out  again  after 
two  hours,  and  the  same  round  is  again  repeated  a  seventh 
and  an  eighth  time,  after  a  similar  interval.  The  next 
day,  they  are  taken  out  twice,  and  even  three  or  four 
times  if  the  hides  are  of  bad  quality,  and  do  not  swell 
readily.  It  is  necessary  to  stir  the  liquor  each  time,  so 
as  to  raise  the  barley-meal  from  the  bottom,  and  to  cover 
the  tubs  immediately  after  putting  in  the  skins.  The 
heat  of  these  tubs  should  be  maintained  at  from  105°  to 
120°  F.,  by  occasional  additions  of  reserved  liquor  kept 
warm  over  the  fire. 

The  hides  are  placed  in  the  tubs  with  the  assistance 
of  two  workmen,  who,  taking  them  by  the  opposite  ends, 
spread  them  out  upon  the  flesh  sides,  and  then  push  them 
down  with  a  pole. 

Experience  has  proved  that  the  action  of  the  white 
dressing  is  completed  in  about  36  hours;  the  acetic  fer- 
mentation, which  is  established,  so  expands  the  hides 
that  they  become  as  thick  as  the  leather  into  which  they 
are  about  to  be  converted.  Care  must  be  taken  not  to 
leave  them  any  longer  in  the  liquor  after  this  point  has 
been  attained,  for  it  injures  the  leather;  a  result  which 
also  takes  place  if  the  liquor  be  too  strong. 

After  the  removal  of  the  skins  from  the  liquor,  the  clear 
portion  of  the  latter  must  be  reserved  for  a  new  dressing, 
for  which  purpose  it  must  be  treated  with  a  complement 


WALLACHIA  LEATHER. 


391 


somewhat  stronger  than  the  first.  This  acid  liquor 
greatly  facilitates  the  fermentation  of  the  new  composi- 
tion, which  sours  rapidly.  In  this  manner,  when  the 
white  dressings  are  once  in  train,  they  may  be  kept  at 
one-half  the  expense  of  flour,  time,  and  money. 

After  being  taken  out  of  the  dressings,  the  hides  are 
left  to  drain  on  the  cover,  and  as  soon  as  they  have  cooled, 
are  soaked  in  water  for  a  few  moments,  in  order  to  effect 
the  removal  of  a  viscous  coating  derived  from  the  bar- 
ley, and  they  are  then  drained  anew.  They  are  now 
subjected  to  the  red  dressing  which  prepares  them  for 
the  tan-vats.  This  dressing  is  made  by  charging  the 
tub  with  about  40  pounds  of  crushed  bark,  into  which, 
mixed  with  water,  the  hides  are  then  to  be  placed.  At 
noon,  they  are  taken  out  and  allowed  to  drain  for  seven 
or  eight  minutes,  and  in  the  evening  again  for  a  quarter 
of  an  hour;  but  before  they  are  put  back  the  last  time, 
the  liquor  must  be  treated  with  40  pounds  more  of 
crushed  bark,  and  thoroughly  stirred.  On  the  mornings 
of  the  second  and  third  days,  24  pounds  of  bark  are 
added :  the  hides  are  taken  out  three  times  daily,  and  an 
interval  of  thirty  minutes  allowed  for  each  draining. 

On  the  fourth  day  they  are  taken  out  only  twice — 
morning  and  evening.  There  is  no  addition  of  bark,  and 
forty-five  minutes  are  allowed  for  draining.  On  the  fifth 
day,  the  hides  are  taken  out  in  the  morning,  and  while 
they  are  draining,  the  liquor  must  be  thoroughly  stirred, 
and  the  hides  returned  to  it,  hair  side  uppermost.  Some 
handfuls  of  bark  are  then  thrown  in  between  each  skin, 
and  on  the  top  of  the  last  one,  which  should  have  its 
flesh  side  uppermost.  The  skins  are  to  be  left  in  this 
state  from  eight  to  ten  days,  then  removed,  rinsed  in 
clear  water,  and  put  into  the  vats. 

This  method,  though  not  popular,  is  still  the  best  in 


392 


WALLACHIA  LEATHER. 


use,  because  the  strength  of  the  liquors  being  greater 
than  that  of  those  generally  employed,  they  are  less 
liable  to  turn,  and  consequently  the  work  is  less  tedious. 

Bran-Dressings. — Some  tanners  contend  that  the  red- 
dressings  may  be  omitted,  if  the  white-dressings  are 
made  with  bran.  The  unanimous  opinion  of  many  tan- 
ners whom  we  have  consulted  on  the  subject,  is  in  favor 
of  red-dressings.  However,  to  complete  the  considera- 
tion of  the  whole  subject,  we  shall  here  describe  the 
method  employed : — 

The  bran-dressings  are  made  either  hot  or  cold.  For 
the  first,  a  leaven  is  prepared  with  the  yeast,  or  made 
with  1  to  li  pounds  of  wheat  or  rye  flour  for  each  hide, 
and  kept  at  a  moderate  temperature. 

The  skins  should  be  freed  from  all  the  adhering  dirt 
and  dung  which  ordinarily  soil  them;  they  are  then 
fleshed  and  dipped.  A  quantity  of  water,  sufficient  for 
a  bath  for  all  the  skins,  is  then  boiled  with  bran,  in  the 
proportion  of  from  seven  to  eight  pounds  for  each  skin. 
The  cover  is  then  placed  upon  the  boiler,  and  when  the 
liquid  has  been  sufficiently  fermented,  which  is  known  by 
the  bran  rising  to  its  surface,  it  is  poured  into  a  vat  in 
which  the  skins,  previously  rinsed,  have  been  deposited. 

While  the  skins  are  getting  warmed,  another  quantity 
of  water  is  heated  over  the  fire  until  it  simmers,  when  it 
is  mixed  with  the  ferment  made  at  the  beginning  of  the 
operation.  The  skins  are  then  taken  out  from  the  bath, 
the  fresh  mixture  is  poured  into  the  vat,  and  is  mixed 
with  salt  in  the  proportion  of  rather  more  than  a  pound 
for  each  skin;  the  whole  is  well  stirred,  and  the  skins 
are  then  deposited  in  it.  After  six  hours,  the  skins  are 
again  taken  out  and  replaced,  after  a  portion  of  the  liquid 
has  been  previously  taken  out,  heated,  and  again  well 
mixed  with  the  contents  of  the  vat;  and  this  operation 


WALLACHIA  LEATHER. 


is  repeated  every  six  hours  during  the  two  succeeding 
days. 

As  soon  as  the  hair  is  ready  to  come  off,  it  is  removed 
from  the  surfaces,  after  which  the  skins  are  passed  over 
lightly  upon  the  flesh,  are  soaked  in  cold  water  for  a 
quarter  of  an  hour,  and  replaced  in  the  vat,  in  which 
they  are  allowed  to  remain  until  sufficiently  raised  ;  care 
being  taken  to  keep  the  vat  perfectly  covered  so  as  to 
retain  its  heat  as  much  as  possible.  By  reheating  a 
portion  of  the  liquor  in  the  vat  from  time  to  time,  and 
keeping  it  warm,  the  raising  will  generally  be  completed 
at  the  end  of  three  days.  The  skins  are  then  rinsed 
and  left  to  soak  for  some  hours  in  fresh  water. 

In  order  to  prepare  the  cold  bran-dressings,  a  ferment 
is  made  with  2  pounds,  3  ounces  of  flour  for  each  skin ; 
it  is  allowed  to  ferment,  and  is  then  diluted  freely  with 
cold  water,  and  the  skins  are  plunged  in  it.  They  are 
taken  out  two  or  three  times  a  week,  being  allowed  to 
drain  each  time  for  a  whole  night,  over  the  vat. 

When  the  hair  is  ready  to  be  detached,  it  is  removed, 
the  skins  are  rinsed,  passed  lightly  over  on  the  flesh  side, 
allowed  to  soak  for  some  hours  in  water,  and  are  de- 
posited again  in  the  vat,  in  order  to  raise  them.  If  this 
process  goes  on  too  slowly,  they  may  be  exposed  to  a 
second  bath  like  the  first.  This  mode  of  proceeding  is 
very  convenient  for  those  who  manufacture  upon  a  small 
scale,  as  it  is  inexpensive,  and  does  not  require  the  use 
of  furnaces  or  boilers.  Skins  can  be  readily  deprived  of 
hair  and  raised  by  it,  but  it  requires  exposure  for  at  least 
two  months. 

Decomposition  of  tlie  White-Dressings. — These  dressings 
may  be  regarded  as  soured  pastes  of  barley,  rye,  or  wheat., 
which,  under  certain  circumstances,  undergo  a  decompo- 
sition precisely  as  milk^  paper-hangers'  paste,  and  other 
26 


394 


WALLACHIA  LEATHER. 


substances  do,  and  it  is  believed  that  lightning  produces 
this  effect  as  it  does  in  the  case  of  milk.  Some  tanners 
are  in  the  habit  of  placing  in  the  vats  scraps  of  old  iron 
enveloped  in  linen  rags,  upon  the  approach  of  a  thunder- 
storm, while  others  dissolve  from  half  a  pound  to  a  pound 
of  sal-ammoniac  in  the  vats,  under  the  belief  that  these 
means  will  prevent  the  injurious  consequences  of  the 
turning  of  the  liquors.  When  this  kind  of  decomposi- 
tion takes  place  in  the  dressings,  they  become  unfit  for 
further  use,  and  would  render  the  skins  so  soft,  loose  and 
spongy  in  texture,  as  to  impair  the  quality  of  the  leather 
made  from  them.  The  long  continuance  of  the  summer 
heats,  is  also  apt  to  cause  this  decomposition,  and  the 
quality  of  the  dressings  is  more  likely  to  be  injured  in 
the  three  summer  months  than  in  all  the  rest  of  the 
year.  Cold  has  no  injurious  influence  upon  them,  fur- 
ther than  that  it  diminishes  their  efficacy,  and  the  skins 
may  be  allowed  to  remain  in  them  even  when  the  sur- 
face is  frozen,  if  they  are  afterwards  replaced  in  fresh 
dressings. 

Rye-Dressings,  as  used  in  Transylvania. — The  Transyl- 
vanian  tanners  dress  their  skins  almost  in  the  same 
manner  as  the  Wallachians,  except  that  while  the  latter 
employ  twenty-two  pounds  of  barley  for  each  skin,  the 
former  make  use  of  twenty  pounds  of  rye-flour,  divided 
into  two  portions  of  eleven  pounds  for  the  first,  and  nine 
pounds  for  the  second  dressing.  This  method  is  less 
expensive  than  the  other,  since  the  rye  grounds  preserve 
their  strength  much  longer  than  the  barley,  owing  to  the 
greater  quantity  of  gluten  contained  in  them. 


CHAPTER  XXXIY. 
MINERAL  TANNING. 

By  reference  to  our  remarks  upon  tannin,  it  will  be 
learned  tliat  the  chemical  property  possessed  by  that 
body,  of  forming  an  insoluble  compound  with  gelatine,  is 
not  limited  solely  to  gelatine,  but  extends  also  to  earthy 
and  metallic  bases.  This  behavior  has  suggested  the 
employment  of  mineral  agents  as  substitutes,  wholly  or 
in  part,  for  bark,  in  a  way  somewhat  similar  to  that  in 
which  alum  is  used  for  tanning;  except  that  the  result- 
ing compound  or  leather  is,  chemically  considered,  a 
rather  more  definite  combination. 

The  advantages  said  to  be  derived  from  this  mode  of 
treating  skins,  are  superior  excellence  of  the  product  as 
to  durability  and  power  of  resisting  water,  economy  of 
time  and  materials,  and  simplicity  of  manipulation.  These 
processes,  although  not  strictly  tanning  ones,  will  be 
referred  to  as  such  in  the  following  pages,  in  order  to 
avoid  circumlocution. 

Of  the  processes  which  may  be  properly  comprised 
under  the  head  of  this  chapter,  some  refer  exclusively 
to  the  use  of  mineral  agents  as  leather-making  materials, 
and  others,  to  their  employment  in  combination  with  the 
usual  tanning  process. 

D'Arcet  and  Ashton  were  the  pioneers  in  mineral 
tanning,  and  they  employed  the  sesqui-sulphate  of  iron, 


396 


MINERAL  TANNING. 


but  in  such  an  unsldlful  manner,  that  their  resulting 
product  was  very  objectionable,  being  only  partially  con- 
verted into  leather,  or  else  having  the  greater  disadvan- 
tages of  crispness  and  want  of  strength. 

Bordier  followed  these  experimenters  with  better  suc- 
cess, and  in  1842,  patented  a  process  of  which  we  now 
proceed  to  give  an  abstract. 

bordier's  process. 

This  method  consists  in  washing,  depilating,  swelling, 
and  bating  or  drenching  the  hides,  as  is  generally  done, 
and  then  subjecting  them  to  the  action  of  such  earthy  or 
metallic  salts  or  bases  as  the  gelatine  and  albumen  may 
have  an  affinity  for.  The  tanning  agent  which  the  in- 
ventor prefers  is  the  subs ulph ate  of  the  peroxide  of  iron, 
which  is  a  compound  of  sulphuric  acid  and  peroxide  of 
iron,  with  the  latter  or  base  in  excess.  The  impreg- 
nating liquor  or  ^^ooze"  is  prepared  by  digesting  twenty- 
two  pounds  of  powdered  green  copperas  {proto-sulpJiate 
of  iron),  with  a  mixture  of  two  and  a  quarter  pounds  of 
nitric  acid  at  36°  Baume  (specific  gravity  1.333),  and 
three  pounds  one  ounce  of  sulphuric  acid  at  66°  Baume 
(specific  gravity  1.848).  The  containing  vessel  should 
be  a  large  jar  of  stone,  heated  by  steam,  and  the  con- 
tents must  be  repeatedly  stirred  during  the  digestion. 
When  the  red  fumes  of  nitrous  gas  cease  to  be  given  ofi", 
the  jar  is  to  be  removed  from  the  steam  bath,  and  the 
stirring  continued  at  short  intervals,  until  the  mixture 
is  cold  and  pasty.  After  twenty-four  hours'  repose,  it  is 
to  be  diluted  with  water  in  sufficient  quantity  to  reduce 
it  to  the  requisite  degree  for  use,  and  mixed  with  an 
excess  of  freshly  prepared  hydrated  peroxide  of  iron. 
After  standing  for  several  days,  and  being  repeatedly 


MINERAL  TANNING. 


397 


stirred  during  the  interval,  the  liquor  is  ready  for  tanning 
purposes.  In  another  process  described  by  the  inventor, 
peroxide  of  manganese  is  used  instead  of  nitric  acid,  to 
pe? -oxidize  the  p?^oto-salt  of  iron. 

By  immersion  in  this  liquid,  properly  diluted,  the 
skins  gradually  become  impregnated  with  the  tanning 
material.  The  duration  of  the  soaking  should  vary 
with  the  thickness  of  the  hide.  Three  days  suffice  for 
thin  skins,  and  six  to  eight  for  sole  leather.  In  this 
operation,  the  subsulphate  of  iron  is  absorbed  by  the 
gelatinous  tissue,  while  free  sulphuric  and  nitric  acids 
remain  in  the  mother  liquor  along  with  any  unimbibed 
iron  salt. 

In  order  to  impart  tenacity,  solidity,  and  impermea- 
bility to  the  leather,  it  must  be  subjected  to  the  currier's 
processes. 

cavalin's  processes. 

1.  Dutch  or  Mineral  Tanning. — This  process  requires 
that  the  skins  shall  be  macerated  first  in  a  liquor  of  alum 
and  chrome  salt,  and  subsequently  in  a  solution  of  proto- 
sulphate  of  iron.  The  reaction  which  ensues  produces 
such  an  interchange  of  the  elements  of  the  iron,  chrome 
salt,  and  alum,  as  to  generate  a  new  compound  or  com- 
pounds of  iron  and  chrome,  which  unite  indissolubly  with 
the  tissue  of  the  hide,  and  convert  it  into  leather.  The 
preliminary  treatment  with  chrome  salt  permits  the  sub- 
stitution of  proto  for  persalt  of  iron  in  the  finishing  bath, 
and  affords  a  leather  which  is  impermeable  to  water,  and 
free  from  brittleness. 

Leather  thus  made,  is  brown,  tough,  and  compact, 
even  after  considerable  soaking,  and  does  not  lump 
under  the  hammer. 


398 


MINERAL  TANNING. 


The  hideSj  after  having  been  soaked  and  undergone 
the  usual  preliminary  process  of  depilation,  swelling  by 
lime,  and  drenching,  are  then  thoroughly  rinsed  in  clear 
water,  and  hung  up  to  drain.  The  use  of  acids  must  be 
avoided  for  swelling,  as  they  are  chemically  incompatible 
with  the  mineral  salts  used  for  the  tanning,  and  would, 
by  decomposing  them,  nullify  their  action  upon  the  gela- 
tinous tissue  of  the  hide. 

In  the  mean  time,  a  bath  is  made  by  dissolving  ten 
pounds  of  bi-chromate  of  potassa,  and  twenty  pounds  of 
alum,  in  one  hundred  and  eighty  pounds  of  water.  As 
soon  as  the  hides  have  drained  sufficiently,  they  are 
immersed  in  this  bath  for  four  days,  or  until  they  are 
thoroughly  colored  and  penetrated  by  the  liquid;  but 
with  the  precaution  of  drawing  them  once  every  twenty- 
four  hours,  allowing  them  to  drain,  and  rubbing  them 
each  time  before  they  are  returned  to  the  bath.  It  is  also 
necessary  to  maintain  the  original  strength  of  the  liquor, 
by  occasional  additions  of  chrome  salt  and  alum,  mixed 
in  the  proportion  of  one  part  of  the  first,  and  two  parts 
of  ths  last. 

The  success  of  the  operation  depends  upon  the  com- 
pleteness of  the  maceration.  Being  assured  of  this,  the 
hides,  as  above  treated,  are  then  subjected  to  the  action 
of  a  bath,  formed  by  dissolving  ten  pounds  of  green 
copperas  (protosulphate  of  iron)  in  sixty  pounds  of  cold 
water.  They  must  be  suspended  in  the  liquor  so  that 
they  shall  not  touch  each  other,  and  are  drawn  out  at 
intervals  of  twelve  hours,  allowed  to  drain,  and  then 
returned  to  the  liquor,  as  often  as  may  be  necessary  for 
the  completion  of  the  tanning.  Upper  leathers  require 
5  to  6,  Swedish  sole,  8  or  10,  and  American  butts,  13  to  19 
days'  immersion  in  the  liquor.  The  strength  of  the  bark 
must  be  maintained  by  occasional  additions  of  copperas 


MINERAL  TANNING. 


399 


tliroughoiit  the  treatment.  After  coming  from  the  bath, 
the  hides  are  hung  up  to  drain,  then  freed  from  slimy 
matter,  and  thoroughly  soaked  in  running  water,  so  as 
•  to  wash  out  all  uncombined  saline  matter  which  would 
"  otherwise  impair  the  suppleness  and  toughness  of  the 
leather.    The  leather  is  finished  in  the  usual  manner. 

Upper  leather,  made  by  this  process,  is  said  to  be 
supple  and  soft.  The  hlacMng,  however,  requires  to  be 
differently  applied  from  that  employed  for  oak-tanned 
leather.  In  the  leather  there  is  always  sufficient  of  tan- 
nin to  produce  a  black  coloring  (tanno-gallate  of  iron) 
upon  'the  surface  when  it  is  washed  over  with  copperas. 
In  mineral  leather,  there  is  no  tannin  used,  nor  is  there 
any  other  material  in  the  tissue  of  the  skin  which  will, 
like  tannin,  in  conjunction  with  iron  salt,  form  the  black 
coloring.  The  black  is  imparted  by  mordanting  the 
leather  with  a  saturated  solution  of  alum,  holding  in  so- 
lution eight  parts  of  copperas,  and  rubbing  over  a  strong 
decoction  of  logwood.  The  leather  is  then  oiled,  and 
finished  in  the  usual  manner. 

2.  Dye-Tanning. — This  process  comprises  two  series  of 
manipulations,  firstly,  the  dyeing;  and  secondly,  the  tan- 
ning. It  is  based  upon  the  fact  that  gelatine,  dissolved 
in  a  decoction  of  Brazil,  Heath,  Fernambuque,  or  other 
dye-wood,  is  precipitated  as  an  insoluble  compound,  on 
the  addition  of  a  little  chrome  salt. 

The  hides,  after  having  been  softened,  depilated,  and 
prepared  in  the  usual  manner,  but  imtliout  the  use  of 
acids,  are  then  dipped  in  a  cold  dj^e-bath,  made  by  ex- 
hausting the  dye-wood  in  a  steam-vat,  and  adding  alum 
to  the  solution  in  the  proportion  of  four  ounces  to  the 
gallon. 

"Skins  and  upper-leather  hides  are  first  dyed  in  the 
grain  in  a  weaker  dye-lye,  composed  of  one  volume  of 


400 


MINERAL  TANNING. 


the  above  strong  dye-lye  and  four  volumes  of  water. 
While  this  dyeing  is  going  on,  the  skins  and  hides  must 
be  frequently  stirred.  After  thus  lying  for  twelve  hours, 
they  are  then  hung  ujd  until  they  have  nearly  lost  their 
moisture,  when  they  are  laid  in  the  strong  lye,  stirred 
there  well  three  or  four  times  a  day,  till  they  are  dyed 
all  through,  a  light  yellow  green  in  the  grain,  and  green 
yellow  quite  through.  Sole-leather  hides,  which  need 
no  stirring,  are  also  first  laid  in  the  weaker  liquor  for 
twelve  hours,  and  then  in  the  strong  lye,  some  dye-wood 
being  placed  between  every  hide,  that  they  may  not 
touch  too  closely.  The  hides  may  then  remain  undis- 
turbed until  they  are  sufficiently  dyed  through,  a  small 
bit  of  the  uppermost  hide  being  cut  off  every  now  and 
then  to  see  how  the  dyeing  is  progressing.  When  circum- 
stances demand  it,  the  strength  of  the  lye  can  be  tested 
by  immersing  therein  a  softened  bit  of  raw  skin,  and 
taking  it  out  after  some  hours  to  see  w^hether  it  is  dyed 
light  yellow  green  or  only  yellow ;  for  in  the  latter  case, 
the  liquor  is  too  weak,  and  wants  either  more  dye 
strength  or  some  alum.  It  must  then  be  drawn  off,  and 
a  new  lye  poured  on.  The  lye  which  has  been  drawn 
off  is  now  tried  again,  and  refreshed  by  the  addition  of 
1-48  of  alum. 

^'  If  a  piece  of  raw-done  skin  is  only  dyed  yellow  in 
this  lye,  it  must  then  be  boiled  again  with  dye-wood,  and 
some  alum  added  to  it  in  the  manner  above  described. 
If  the  bit  of  skin,  on  the  contrary,  is  dyed  green  yellow, 
the  mixture  need  not  be  reboiled  with  dye-wood,  but 
only  increased  in  strength  by  the  addition  of  1-48  to 
1-32  of  alum." 

The  hides  are  then  hung  up  to  drain  previous  to  being 
immersed  in  the  chrome  bath,  which  consists  of  a  solu- 


MINERAL  TANNIK^G. 


401 


tion  of  10  pounds  of  bichromate  of  potassa  in  180 
pounds  of  cold  water. 

The  requisite  time  for  the  completion  of  the  soaking, 
is  about  twenty-four  hours;  but  it  is  necessary  to  handle 
the  hides  frequently,  and  to  draw  and  allow  them  to 
drip  three  or  four  times  during  the  treatment.  The  bath 
must  also  be  refreshed  by  occasional  additions  of  chrome 
salt. 

The  action  of  the  chrome  salt  effects  the  tanning,  and, 
with  the  assistance  of  the  alum,  darkens  the  color  of  the 
hides.  After  coming  from  the  chrome  bath,  they  are 
hung  up  to  drain,  carefully  smoothed,  thoroughly  soaked 
three  several  times  in  fresh  or  running  waters,  for  12  to 
24  hours,  then  cleansed  on  the  beam,  and  suspended  in 
the  drying-room.  They  are  then  dampened,  stretched, 
worked  on  the  flesh  side  with  train  oil ;  half  dried,  again 
stretched,  and  blacked  on  the  surface  as  directed  in 
mineral  tanning. 

It  is  doubtful  whether  leather  made  by  any  of  the  pre- 
ceeding  processes  will  preserve  its  durability  for  any 
length  of  time;  as,  from  its  very  nature,  it  would  be 
reasonable  to  expect  it  to  crack,  unless  it  be  kept  con- 
stantly greased.  It  possesses  this  advantage,  however, 
that  when  worn  by  long  service,  the  debris  are  still 
useful  as  glue  pieces,  for  they  may  readily  be  recon- 
verted into  their  original  condition  of  raw  hide,  by  the 
removal  of  the  basic  salts  which  maintain  them  in  the 
state  of  leather. 

Newton's  process. 

This  method,  patented  in  1849,  is  an  accelerating 
process,  somewhat  analogous  to  the  preceding.  It  con- 
sists in  the  employment  of  certain  earthy,  alkaline,  or 


402 


MINERAL  TANNING. 


metallic  salts  for  tlie  preliminary  treatment;  and  of  ca- 
techu, sumach,  oak-bark,  or  other  astringent  matter  for 
the  tanning.  The  joint  action  of  the  salts  and  the  tan- 
ning material  promotes  the  combination  of  the  albumi- 
nous matter  of  the  skins  with  the  bases,  and  subsequently, 
of  the  gelatine  tissue  with  the  tannin.  When  other  ma- 
terial than  catechu  is  used,  the  latter  of  good  quality, 
and  containing  50  per  cent,  of  tannin,  is  taken  as  the 
standard  for  regulating  the  proper  proportion  of  the 
former.  The  skins  must  be  unhaired,  and  free  from 
lime. 

For  100  calf-skins. 

20  pounds  Alum,  and 
10     "      Common  Salt; 
100     "  Catechu; 

4     "      Sulphate  of  Alumina,  either  alone  or 
mixed  with  2  pounds  common  salt. 

The  three  mixtures  are  dissolved  in  water,  and  kept 
apart  in  separate  vessels. 

Of  the  first  solution,  one-fifth;  of  the  second,  one- 
tenth;  and  of  the  third,  one-fourth  are  placed  in  a  vat. 
The  skins  are  then  immersed  in  this  liquor,  and  repeat- 
edly handled  or  stirred  about  for  a  short  time,  after 
which  they  are  taken  out.  The  vat  is  then  refreshed  by 
the  addition  of  one-fifth  of  the  first  solution,  one-tenth 
of  the  second,  and  one-fourth  of  the  third,  and  the  skins 
replaced  in  the  mixture,  and  treated  as  before,  but  for  a 
longer  interval.  The  skins  being  removed  a  second 
time,  the  vat  is  again  refreshed  with  one-fifth  of  the  first 
solution,  and  one-tenth  of  the  second ;  and  the  skins  re- 
immersed  in  it  as  in  the  previous  instance.  After  remain- 
ing for  some  time,  and  being  handled  occasionally,  they 
are  again  removed,  and  the  residues  of  the  first  and  third 


MINERAL  TANNING. 


403 


solutions,  and  one-fifth  of  the  second  are  poured  into  the 
vat.  The  skins  are  then  put  back,  but  in  a  few  daj^s 
are  again  taken  out  to  allow  the  addition  to  the  vat  of 
the  remaining  two-fifths  of  the  second  mixture.  Four 
or  five  weeks  suffice  to  complete  the  tanning  of  the  skins. 

The  author  suggests  that  the  process  may  be  modified 
by  laying  the  skins  in  a  vat,  and  stratifying  them  with 
8  lbs.  of  moistened  tan.  The  constant  contact  of  the  tan- 
ning liquor  would  have  to  be  maintained  by  pumping  it 
from  the  bottom  of  the  vat  to  the  top  of  the  skins. 

This  process  is  applicable  to  the  tanning  of  other  skins, 
but  the  proportions  of  materials  require  to  be  varied,  as 
follows :  The  proper  quantities  for 

One  hundred  goat-skins,  are 

Alum     .  ,  .       10  to  12  lbs. 

Salt       ...         6  lbs. 
Catechu  .  .  .       50  to  60  lbs. 

For  one  hundred  cow-hides,  are 

Sulphate  of  Alumina        .  2  to  300  lbs. 

Salt  .  .  .       100  lbs. 

Catechu    .  .  .500  " 

For  one  hundred  and  ninety  ox-hides,  are 

Sulphate  of  Alumina  .       14  to  16  lbs. 

Salt  ....         8  lbs. 
Catechu        .  .  .       60  to  70  lbs. 

Sulphate  of  magnesia  or  chloride  of  zinc  may  be  sub- 
stituted for  sulphate  of  alumina. 


CHAPTER  XXXV. 


THE  TEXTUEE  AND  QUALITY  OF  LEATHER,  AND  THE 
MEANS  OF  DISCOYERINa  ITS  DEFECTS. 

It  is  evident  from  what  has  already  been  observed, 
that  well-tanned  leather  is  a  homogeneous  substance, 
entirely  free  from  unchanged  gelatine  or  fibrine.  But  if 
the  bark  used  in  its  preparation  has  been  deficient  in 
tanning  ingredients,  or  otherwise  wanting  in  quality ; 
if  the  various  processes  have  been  imperfectly  or  care- 
lessly performed,  or  if  unforeseen  accidents  have  oc- 
curred, the  excellence  of  the  leather  is  impaired ;  and 
this  is  generally  to  be  discovered  by  making  a  section  of 
it.  Well-tanned  leather  exhibits,  when  cut,  a  shining 
surface  and  compact  body;  is  of  a  uniform  color,  except- 
ing upon  the  hair  side,  and  has  a  nutmeg  appearance 
internally.  These  signs  are  commonly  looked  for  in  the 
tail,  the  back,  and  the  neck,  which  are  the  thickest  parts 
of  the  skin. 

Badly  made  or  inferior  leather  is  commonly  detected 
by  its  section  being  of  a  yellowish  or  blackish  color, 
alternating  with  streaks  of  a  black  or  whitish  hue,  and 
by  its  structure  being  loose  and  deficient  in  density  and 
compactness. 

Too  long  a  continuance  in  the  tan-vats  or  lime-pits, 
badly  prepared  or  applied  dressings,"  want  of  moisture 
in  the  pits,  and  a  number  of  other  circumstances,  give 


TEXTURE  AND  QUALITY  OF  LEATHER. 


405 


to  leather  a  spongy  and  loose  texture,  and  render  it  de- 
ficient in  the  requisite  color  and  durability.  These 
defects  are  of  such  a  nature  that,  when  once  tanned,  the 
leather  cannot  be  improved  or  restored  to  a  better  con- 
dition. 

It  is  impossible  to  thoroughly  tan  those  hides  which 
are  thin,  poor,  and  weak,  and  such,  in  general,  as,  either 
from  natural  defects  or  want  of  correct  management, 
cannot  be  properly  raised. 

Other  conditions  of  skins,  unfitting  them  in  a  measure 
for  the  tanning  process,  arise  from  injuries  received  in 
the  slaughter-house,  from  soaking  in  muddy  or  slimy 
waters ;  from  foreign  matters  imbedded  in  the  hair  side, 
which  subjects  their  surface  to  bruises  when  they  are 
being  worked  on  the  beam,  and  from  weakness  of  texture, 
owing  to  incipient  decomposition,  by  a  too  long  exposure 
in  the  lime-pits.  Old  moss-covered  bark,  which  is  full 
of  cracks,  charged  with  moisture,  also  injures  the  quality 
of  leather.  The  opposite  and  equally  injurious  circum- 
stance of  deficient  watering  of  the  pits,  has  already  been 
sufficiently  censured. 

Notwithstanding  the  arguments  hazarded  by  some 
tanners  in  favor  of  the  use  of  the  impure  waters  of  cer- 
tain localities,  there  can  be  no  doubt  of  the  fact  that  the 
freshest  and  purest  water  that  can  be  employed,  is  the 
best  for  the  preparation  of  leather. 

Manufacturers  differ  among  themselves  in  opinion 
about  the  effect  produced  by  cold  weather  upon  their 
leather ;  some  contending  that  it  softens  the  tissue,  and 
that  it  is  only  necessary  to  expose  poor  and  thin  skins, 
and  those  which  are  otherwise  difficult  to  manage,  to 
cold,  in  order  to  make  them  soft,  and  put  them  in  a 
condition  to  be  worked.  Others  maintain  that  extreme 
cold,  by  congealing  and  expanding  the  water  contained  in 


406  TEXTURE  AND  QUALITY  OF  LEATHER. 


the  tissues,  extends  and  separates  the  particles,  and  thus 
impairs  the  body  and  firmness  of  the  leather. 

Some  hides  are  called  liorny^  parts  of  which,  from 
want  of  proper  softening,  are  dry,  and  almost  as  hard  as 
horn;  and  these  are  entirely  unfit  for  shoe  or  boot 
leather,  as  the  tan  has  not  perfectly  penetrated  the  hard 
parts.  Others  contain  extremely  minute  perforations 
made  by  worms,  which  allow  water  to  filter  through, 
and  render  them  useless  for  either  sole  leather  or  car- 
riage-tops. Many  hides  are  injured  by  the  carelessness 
of  the  butchers,  who  damage  the  flesh  side  by  a  reckless 
manner  of  skinning.  These  imperfections  can  only  be 
remedied  by  shaving  the  surface  down  to  a  uniform 
thickness,  with  a  scraping  knife,  at  the  risk  of  making 
the  hide  thin  and  weak. 

Shoemakers  using  sole  leather,  which  has  been  made 
from  hides  damaged  upon  the  hair  side,  either  in  depi- 
lating, in  paring,  or  in  rinsing  them,  should  be  careful 
to  place  the  flesh  side  out;  otherwise,  as  soon  as  the  hair 
surface  has  become  a  little  worn,  the  sole  will  become 
spongy,  and  easily  absorb  moisture. 

A  common  mode  of  determining  the  quality  of  leather, 
is  to  allow  a  drop  of  water  to  fall  from  the  end  of  the 
finger  upon  the  hair  side,  or  upon  a  cut  surface;  if  the 
drop  preserves  its  circular  form,  and  does  not  extend, 
the  leather  is  supposed  to  be  well  tanned,  while  if  the 
water  is  soon  absorbed,  it  is  regarded  as  an  evidence  of 
its  substance  being  spongy  and  badly  prepared.  A  better 
test  is  to  allow  a  piece  of  the  leather,  the  weight  of 
which  has  been  accurately  ascertained,  to  soak  for  some 
days  in  water.  If,  after  being  taken  out,  it  is  found  con- 
siderably increased  in  weight,  no  better  proof  of  its 
being  spongy  and  loose  in  texture,  and  consequently 
imperfectly  prepared,  could  be  desired. 


TEXTURE  AND  QUALITY  OF  LEATHER. 


407 


It  is  believed,  by  some,  that  leather  is  improved  in 
quality,  by  age,  and  it  is  a  common  reproach  against 
shoemakers,  that  they  make  use  of  too  fresh  materials. 
Exposure  for  a  certain  length  of  time  is  doubtless  ad- 
vantageous, but  leather  is  not  improved  by  being  kept 
longer  than  two  years,  and  is  apt  after  this  time  to  dry 
and  to  diminish  in  weight,  making  it  necessary  to  store 
it  in  damp  cellars.  The  resistance  and  durability  of  the 
leather  made  into  soles  of  boots  and  shoes,  are  much 
increased  by  their  being  laid  aside  for  some  time  before 
being  worn. 

The  coloring  of  leather  during  the  process  of  tanning, 
arises  from  a  dark  brown  substance,  existing  more  or 
less  in  the  infusions  of  tanning  materials,  and  called  by 
Berzelius,  apotlieme.  This  sparingly  soluble  substance 
is  generated  by  the  oxidation  of  extractive  matter,  and 
is  gradually  formed  when  infusions  of  tanning  materials 
are  exposed  to  the  air,  all  the  varieties  of  tannin  being, 
to  a  certain  extent,  liable  to  this  transformation. 
Hence  it  is,  that  the  uppermost  hide  of  the  vat,  being 
the  most  exposed,  is  the  most  highly  colored. 

This  color,  or  "bloom,"  as  it  is  technically  termed, 
varies  somewhat  with  the  kind  of  tannin  employed. 
For  example,  leather  tanned  with  material  containing  the 
gall  variety  of  tannin  is  bloomed  with  ellagic  acid,  and 
that  made  from  catechu  tannin  is  bloomed  with  catechuic 
acid,  both  of  which  coloring  matters  are  derivatives  or 
products  of  the  decomposition  of  the  tannins  respectively 
employed. 

Spent  liquors  or  weak  Jiandlers,  yield  less  "bloom" 
than  the  strong  "bloomers,"  which  are  richer  in  tannin. 

"  Bloom"  attaches  itself,  permanently,  to  the  animal 
tissue,  and  even  penetrates  beneath  the  surface,  to  a 
limited  depth,  imparting  both  color  and  weight  to  the 


408 


TEXTURE  AND  QUALITY  OF  LEATHER. 


leather.  The  fawn  color  is  the  favorite  bloom,  but  a 
darker  shade  does  not  necessarily  indicate  an  inferior 
leather. 

In  the  modern  or  quick  processes,  the  tan-liquor  being 
exposed  for  a  much  shorter  time,  yields  less  bloom  than 
by  the  old  and  lengthy  methods  of  tanning.  Conse- 
quently, as  time  is  an  important  element  in  the  form- 
ation of  this  substance,  its  absence  is  considered  an 
evidence  of  the  inferiority  of  the  leather,  and  that  it 
has  been  tanned  too  rapidly  to  be  good. 


CHAPTER  XXXVI. 


The  tawing  process  is  applicable  to  the  manufacture 
of  soft  leathers  for  gloves  and  furriers'  use,  as  skins  may 
be  subjected  to  its  action  even  in  their  hair  state.  The 
prepared  product  sometimes  takes  the  name  of  "alumed 
leather/'  because  a  salt  of  alumina  is  the  basis  of  the 
process.  Sheep,  lamb,  kid,  and  other  light  skins  are 
those  usually  subjected  to  this  treatment. 

Kid  Leather. — The  first  step  in  the  aluming  of  kid 
skins  is  to  soak  them  well  in  running  water,  and  then 
to  "  break"  them  upon  the  beam  by  working  on  the  flesh 
side  with  the  back  of  the  fleshing-knife.  After  this 
treatment,  drying  must  immediately  ensue,  to  prevent 
putrefaction,  which  would  render  them  spotted  and  ten- 
der. Dry  skins  require  soaking  for  at  least  one  or  two 
days. 

The  next  step  is  to  rub  the  flesh  sides  with  cold  milk 
of  lime,  place  them  back  to  back  in  pairs  with  the  hair 
outwards,  stack  these  pairs  in  piles,  and  thus  leave  them 
for  several  days  until  the  hair  "gives"  readily.  They 
are  then  rinsed  in  running  water  to  remove  lime,  and 
subjected,  at  once,  to  the  fleecing  operation,  which  con- 
sists in  "plucking"  out  the  hair  with  spring  tweezers^ 
and  smoothing  by  rubbing  with  a  whetstone  or  rolling- 
pin.  A  further  cleansing  and  soaking  is  then  given  by 
27 


410  TAWING. 

an  immersion,  as  before,  in  the  lime-vat,  whence,  after 
being  removed,  they  are  transferred  to  an  old  or  weaker 
vat,  and  there  remain  for  a  fortnight  or  more,  care  being 
observed  to  take  them  out,  and  drain  them  frequently. 

They  are  now  ready  for  the  hranning ;  and  for  this 
purpose  undergo  a  steeping,  for  ten  or  fifteen  days,  in  a 
fermenting  mixture,  or  "drench,"  of  forty  pounds  of  bran 
and  twenty  gallons  of  water.  As  soon  as  the  skins  sink  in 
water,  they  are  sufficiently  raised;  and  this  requires  two 
days  in  summer,  and  double  that  number  in  winter ;  and 
great  care  is  necessary  to  observe  when  they  reach  that 
stage,  which  may  be  attained  much  earlier  by  frequently 
turning  the  skins  during  the  steeping. 

When  taken  from  this  liquor,  they  are  to  be  put  into 
the  "  white-bath,"  composed,  for  one  hundred  skins,  of  a 
boiUng  solution  of  twelve  to  eighteen  pounds  of  alum  in 
twelve  gallons  of  water,  to  which  must  be  added  of  com- 
mon salt,  two  and  one-half  pounds  in  summer,  and  three 
pounds  in  winter. 

The  mode  of  working  this  bath  is  to  divide  the  skins 
into  four  equal  parcels,  and  to  pass  each  parcel,  sepa- 
ratel}^  but  successively,  through  the  bath,  and  then  to 
immerse  the  whole  together  for  ten  minutes. 

A  paste  is  then  made  by  gradually  adding,  during 
careful  and  constant  stirring,  firstly,  fifteen  pounds  of 
wheat  flour  to  the  above  alum-bath  gently  heated,  and  sub- 
sequently, the  yolks  of  fifty  eggs,  and  then  incorporating 
the  whole  thoroughly.  The  skins,  after  being  passed 
through  this  paste  singly,  are  then  transferred  to  it  in 
bulk,  and  left  for  a  day. 

The  paste  has  an  emulsive  action,  softens  and  whitens 
the  skins,  counteracts  the  hardening  influence  of  after 
exposure  to  the  air,  and  tendency  to  brittleness. 

After  the  action  of  the  paste,  the  skins  are  stretched 


TAWING. 


411 


upon  poles  in  a  drying  loft,  and  there  left  for  a  week  or 
morej  as  may  be  necessary.  They  are  then  ready  to  be 
worked  upon  the  softenmg  iron,  in  order  to  stretch  them, 
reduce  unevennesses,  and  develop  whiteness.  To  this 
end,  they  are  soaked  in  water  for  five  or  six  minutes, 
and  then  spread  and  softened  by  the  process  of  stale- 
ing. 

They  are  next  stretched  on  hooks,  dried,  and  worked 
on  the  stretching  iron;  but  some  French  tanners,  previous 
to  these  operations,  and  just  after  the  skins  come  from 
the  smoothing  iron,  spread  them  upon  the  beam  with  a 
clean,  undressed  skin  beneath,  and  work  them  with  the 
fleshing-knife. 

Occasionally,  the  prepared  skins  are  polished  by  being 
rubbed  with  pumice.  The  lustre  and  finishing  stroke 
are  given  with  a  smooth  flat-iron,  carefully  heated,  and 
managed  in  the  same  way  as  that  used  by  a  laundress. 

In  some  places,  the  tanning  process  is  slightly  modi- 
fied. For  example,  by  the  use  of  a  large  barrel-churn, 
or  roundabout,  which  receives  both  the  skins  and  alum- 
bath.  Kapid  rotation  of  the  apparatus  promotes  con- 
stant contact  of  the  skins  and  tanning  material,  and 
thus  accelerates  the  operation. 

The  tanned  skins,  after  coming  from  the  egg  paste, 
and  being  washed  and  dried,  are  subjected  to  what  is 
technically  termed  stahing.  This  consists  in  the  use 
of  a  semicircular  iron  plate,  fixed  perpendicularly,  with 
its  round  edge  uppermost,  to  the  top  of  a  wooden  stake 
about  thirty  inches  in  height.  The  workman,  holding 
the  skin  distended  by  both  hands,  draws  it  forcibly  (Fig. 
118),  and  in  every  direction,  over  the  blunt  edge  of  this 
tool,  and  thus  imparts  softness  and  smoothness  to  it. 

Color  can  be  imparted  with  dye-stuffs,  as  may  be 
desired. 


412 


TAWING. 


The  tawed  leather  is  the  raw  skm  combined  with 
subchloride  of  aluminum.  This  latter  salt  is  formed  by 
mutual  decomposition  of  the  ingredients  of  the  alum- 
bath.  For  example,  the  common  salt,  which,  chemi- 
cally speaking,  is  a  compound  of  chlorine  and  sodium, 
when  mixed  with  alum,  which  is  composed  of  sulphuric 
acid  and  oxides  of  aluminum  and  potassium,  gives  up 
its  chlorine  to  the  aluminum.  This  latter  base  having 
deserted  its  oxygen  and  sulphuric  acid,  they  in  turn  take 
up  with  the  potassium  and  sodium,  and  form  sulphate  of 
potassa  and  sulphate  of  soda.  These  remain  in  solution 
in  the  water  along  with  a  perchloride  of  aluminum,  the 
neutral  chloride  first  generated  being  converted,  in  its 
reaction  upon  the  animal  tissue,  into  a  subchloride  which 
combines  with  it,  and  a  perchloride  which  is  soluble. 
The  salt  also  aids  in  whitening  the  skins. 

Imitation  Kid, — Imitation  kid  leather  is  made  from 
lamb-skins.  In  order  to  remove  the  wool  without  in- 
juring it,  lime  is  not  used  for  depilation.  After  the 
skins  have  been  steeped  in  water,  and  "  broken"  on  the 


TAWING.  413 

flesh  side,  they  are  suspended  in  a  subterranean  vault 
about  twelve  feet  square,  protected  as  much  as  possible 
from  the  influence  of  external  atmospheric  changes,  so 
that  the  temperature  within  may  continue  uniform 
throughout  the  year.  An  incipient  putrefaction  being 
thus  promoted,  loosens  the  roots  of  the  wool,  which  may 
then  be  readily  plucked  from  the  pelt;  and  as  soon  as 
this  state  is  reached,  which  is  generally  in  from  five 
to  seven  days,  the  skins  must  be  immediately  removed, 
for  a  continuance  of  the  fermentation  would  injure  their 
texture. 

The  skins  are  then  sllined,  as  it  is  termed,  or  scraped  on 
the  fleshed  side ;  stripped  of  wool,  and  steeped  for  a  week, 
more  or  less,  in  lime-water,  fleshed  on  the  beam,  drenclied 
for  some  days  in  a  fermenting  bran-bath,  and  then  treated 
with  alum  and  salt  in  the  same  manner  as  for  true  kid 
leather.  Dyeing,  softening,  and  polishing  complete  the 
preparation  of  the  leather. 

Housings  and  Mats, — Skins  are  frequently  tanned  with 
the  hair  on,  for  housings  and  mats,  and  for  furriers'  use. 
Sheep,  lamb,  calf,  and  goat  skins,  may  each  be  treated 
by  this  process,  in  which,  consequently,  lime  and  liming 
must  be  dispensed  with,  as  it  would  prove  injurious  to 
the  hair.  The  skins  are  soaked  in  water  until  clean  and 
soft,  are  then  thinned  on  the  flesh  side  with  the  fleshing- 
knife,  and  steeped  for  several  days  in  an  old  bran-bath, 
and  washed.  They  are  then  folded  with  the  hair  sides 
in  contact,  immersed  in  the  alum-bath,  as  before  directed, 
and  spread  over,  upon  the  flesh  side,  with  the  egg  paste. 
After  remaining  in  this  state  for  eighteen  to  twenty 
hours,  and  becoming  stiff,  they  are  hung  up  to  dry. 
They  are  next  sprinkled  with  cold  water,  folded,  and 
stacked,  and  put  under  a  pressure  of  heavy  boards  for 
two  days.    After  being  opened  with  a  round  iron,  upon 


414 


TAWING. 


the  beam,  and  worked  breadthwise  on  the  stretching 
iron,  they  are  dried  by  exposure  of  the  fleece  side  to  the 
sun,  and  finished  upon  the  stretcher. 

Eighteen  pounds  of  ahim  suffice  for  100  sheep-skins; 
but  as  the  thickness  of  the  skins  increases,  the  quantity 
of  tanning  material  must  be  augmented.  A  calf-skin, 
for  example,  requires  one  pound  of  salt  and  one  pound 
of  alum. 


« 


CHAPTER  XXXYII. 
HUNGARY  LEATHER. 

The  Hungarian  method  of  preparing  skins,  which  is 
analogous  to  tanning,  is  said  to  have  been  originally  in- 
troduced into  Hungary  from  Senegal.  It  was  carried 
into  France  in  1573,  by  Boucher,  a  tanner.  In  the  next 
century,  Colbert,  the  great  patron  of  the  industrial  arts, 
gave  particular  encouragement  to  this  process,  and  esta- 
blished a  manufactory  at  St.  Cloud,  in  which  it  was 
adopted.  This  establishment  was  removed,  in  1702,  to 
la  Roquette,  Faubourg  St.  Antoine,  where  it  was  for  a 
long  time  in  successful  operation. 

Hungary  leather  is  manufactured  by  a.  rapid  process, 
which  consists  in  impregnating  strong  hides  with  alum, 
common  salt,  and  suet,  and  which  is  almost  the  same  at 
the  present  day  as  that  originally  employed  when  first 
introduced  from  Hungary;  only  one  improvement  upon 
the  method  having  been  since  proposed,  that  of  Curan- 
deau,  which  will  be  described  in  the  proper  place.  The 
leather  is  manufactured  at  all  seasons  of  the  year,  any 
injurious  influences  which  temperature  might  exert  upon 
it,  being  counteracted  by  measures  which  the  experience 
of  the  workmen  leads  them  to  adopt. 

The  workshop  in  which  skins  are  prepared  by  this 
method,  consists  of  two  parts.  One  of  these  is  a  shed 
on  the  banks  of  a  stream,  in  which  are  placed  the  beams. 


416 


HUNGARY  LEATHER. 


the  fleshing  and  paring  knives,  and  the  scraping  stones. 
In  one  corner  is  a  furnace  with  a  boiler  for  preparing  the 
solution  of  alum,  and  near  it  are  placed  two  tubs  for 
immersing  the  skins.  Besides  these,  a  number  of  ordi- 
nary tubs  are  required. 

The  other  part  of  the  factory  consists  of  a  room  6i 
feet  high,  and  161  feet  square,  made  perfectly  tight,  so 
as  to  retain  the  heated  air.  In  one  corner  of  this  apart- 
ment is  a  furnace,  which  is  fed  with  fuel  through  a  door 
opening  externally,  and  upon  which  is  placed  a  copper 
boiler,  capable  of  containing  about  180  pounds  of  tallow. 

In  the  middle  of  the  room  is  a  square  stone,  upon 
which  an  iron  grating,  3i  feet  square,  is  placed  for  the 
reception  of  coals  (Fig.  119).     On  either  side  of  the 

Fig.  119. 



J I  I  I  I 
I  I  I  I  I  I  I 
I  I  I  I  i  I  I 
—liiiii 
I  I  I  I  I  I  i 
I  I  I  I  I  I  I 
I  I  I  I  I  I  I 
I  I  I  I  I  n 
I  ri  I  I  I  i 
I  M  I  M  ! 


room,  and  occupying  its  whole  length,  are  large  tables, 
upon  which  the  skins  are  greased.  The  upper  part  below 
the  ceiling  is  filled  with  poles,  upon  which  the  leather 
is  hung  in  order  to  be  heated  and  dried.  The  door  of 
the  apartment  fits  closely  to  its  jambs,  so  as  to  prevent 
the  entrance  of  cold  air. 

The  chief  operations  to  which  hides  prepared  after  the 
method  of  Hungary  are  subjected,  are  the  following: — 

1.  The  cleaning,  dipping,  and  rinsing. 

2.  Aluming. 

3.  Second  aluming. 

4.  Drying. 


HIINGART  LEATHER. 


417 


5.  Stretching. 

6.  Treading  out. 

7.  Tallowing. 

8.  Flaming. 

9.  Airing. 

10.  Weighing,  marking,  and  piling. 

These  operations  will  be  successively  described  under 
their  appropriate  headings. 

Strong  ox-hides  are  the  most  suitable  for  the  leather 
of  Hungary,  but  bull  and  cow  skins  may  be  prepared 
for  particular  uses.  The  process  is  a  rapid  one,  and  may 
be  completed  in  two  months  or  less  time.  Hungarian 
hides  can  scarcely  be  compared  with  those  tanned  and 
curried  in  the  ordinary  way,  since  they  consist  of  the 
original  tissue  of  the  skins,  condensed^  and  slightly 
altered  in  character,  by  the  processes  to  which  they  are 
subjected,  but  not  converted  into  true  leather  by  combi- 
nation with  tannin.  Moreover,  they  are  usually  employed 
for  different  purposes. 

1.  Preparation  of  the  Hides, — The  first  operations  are 
analogous  to  those  of  tanning  and  tawing.  The  hides 
are  washed,  cut  in  half,  scraped  upon  the  horse  with  a 
round  or  curved  knife,  and  are  then  carefully  and  slightly 
fleshed,  the  fat  and  flesh  alone  being  removed,  this  and 
the  succeeding  operation  being  confided  to  the  most 
skilful  workmen. 

The  hair  is  then  scraped  off  from  the  hides,  by  j)lacing 
them  upon  a  bed  of  other  skins,  folded  double,  and  so 
disposed  upon  the  horse  (Fig.  120)  as  to  present  a 
smooth,  and  perfectly  uniform  surface.  This  operation 
must  be  conducted  with  the  utmost  care,  to  avoid  injur- 
ing the  surfaces,  and  a  whole  day  will  be  occupied  by  a 
single  workman  in  separating  the  hair  from  eight  or  ten 


418  HUNGARY  LEATHJR. 


Fig.  120. 


hides.  The  skins  are  then  put  to  soak  in  the  river  for 
twenty-four  hours^  or,  if  in  vats,  for  three  days;  the 
water,  in  that  case,  being  changed  twice  a  day  in  summer, 
and  once  daily  in  winter.  If  soaked  in  running  water,  a 
stake  is  driven  into  the  ground  and  the  hides  are  fastened 
to  it  by  cords  passing  through  the  eye-holes,  or  those 
left  by  the  removal  of  the  horns. 

2.  Aluming  the  Hides. — The  preparation  with  alum  is 
the  most  important  one  to  which  Hungary  leather  is  sub- 
jected. It  not  only  prevents  the  putrefaction  of  the 
hides,  but  effects  a  chemical  change  in  them  by  which 
they  are  rendered  stronger  and  more  substantial.  The 
exact  nature  of  this  chemical  influence  is  not  known, 
but  the  supposed  reaction  is  as  explained  under  kid 
leather. 

The  hides  are  first  treated  with  a  mixture  of  alum 
and  common  salt,  by  which  a  portion  of  the  sulphate  is 
converted  into  chloride  of  aluminum.  The  salt  softens 
the  effect  of  the  alum,  attracts  the  moisture  of  the  atmo- 
sphere, and  preserves  the  suppleness  of  the  leather. 

When  the  hides  are  ready  for  the  operation,  the  aque- 
ous solution  of  alum  and  salt  is  made  in  a  boiler  fitted 
into  the  furnace.    This  boiler  (Fig.  121),  should  be  pro- 


HUNGARY  LEATHER. 


419 


portioned  in  size  to  the  number  of  pieces  of  hide  which 
are  to  be  alumed  in  a  single  operation. 

Fig.  121. 


Six  pounds  of  alum,  three  and  a  half  pounds  of  salt, 
and  nearly  eight  gallons  of  water  are  used  for  a  piece  of 
hide  weighing  from  seventy  to  eighty  pounds. 

The  water  is  first  heated  to  about  122°  F.  The  alum 
and  salt  are  then  thrown  in,  and  the  whole  thoroughly 
stirred  until  they  are  dissolved.    The  vats  (Fig.  122) 


Fig.  122. 


are  two  in  number,  placed  side  by  side,  and  each  about 
five  and  a  half  feet  long,  a  yard  wide,  and  two  feet  eight 
inches  deep.  When  nine  hides  or  eighteen  strips  are 
worked  together,  they  are  divided  into  three  lots  of  six 
strips  each.  Three  strips  are  placed  in  each  vat,  being 
prepared  upon  each  other  with  the  hair  side  up,  and  so 
arranged  that  the  head  of  the  second  one  is  above  the 
tail  of  the  first,  and  so  on.    Two  or  three  buckets-full  of 


420 


HUNGARY  LEATHER. 


the  alum  liquor,  tepid  but  not  hot,  are  now  thrown  into 
each  of  the  vats,  and  the  skins  are  tramped  upon  by 
the  workmen,  walking  in  bare  feet  with  a  stamping  mo- 
tion repeatedly  from  one  end  of  each  vat  to  the  other ; 
the  uppermost  hide  when  well  tramped,  being  pushed 
backwards  and  forwards  from  one  end  of  the  vat  to  the 
other.  The  upper  hide,  after  having  been  stamped,  is 
folded  up  and  removed,  so  that  the  second,  and  after  it 
in  due  course  the  lower  hide,  may  have  the  benefit  of 
the  same  treatment,  to  which  end  the  stamping  must  be 
repeated  as  many  times  as  there  are  hides.  The  alum 
liquor  is  then  dipped  up  from  the  vats,  and  thrown  into 
the  boiler,  which  has  been  kept  heated.  When  the  tem- 
perature has  risen  rather  higher  than  that  of  the  liquor 
first  used,  two  or  three  buckets-full  are  again  poured 
into  the  vats,  and  the  same  process  of  tramping  is  re- 
peated. The  hides  are  trod  out  in  a  similar  manner,  a 
third  and  a  fourth  time,  in  liquor  reheated  and  replaced 
in  the  vats  as  before,  its  temperature  being  more  and 
more  elevated  each  time. 

After  the  fourth  tramping,  the  hides  are  folded  double, 
and  deposited  in  tubs  two  feet  eight  inches  in  diameter 
and  the  same  in  height  (Fig.  123),  and  the  alum 
liquor  which  has  already  been  used  is  poured 
over  them.  The  hides  remain  immersed  in  the 
alum  water  for  eight  days ;  their  position  being 
changed  every  day  or  two.  They  are  steeped 
for  a  much  longer  time  in  winter  by  some  manufactu- 
rers. But  no  difference  need  be  made  in  this  respect 
between  the  seasons. 

3.  The  Second  Aluming. — After  being  removed  from 
the  tubs,  and  well  shaken  to  remove  the  folds,  the  hides 
are  subjected  to  the  same  round  of  operations  as  in  the 
first  aluming.    They  are  steeped  for  twenty-four  hours 


HUNGARY  LEATHER. 


421 


in  the  same  alum  water,  and  are  taken  out,  and  left  to 
drain  on  planks  which  are  arranged  in  a  slanting  posi- 
tion, so  that  the  fluids  escaping  from  the  hides  run  back 
into  the  vats. 

4  and  5.  Drying  and  Stretching. — When  the  alum 
water  has  ceased  to  drop  from  the  hides,  four  holes  are 
made  in  each  strip,  and  a  stick  is  thrust  through  them, 
which  is  supported  by  its  two  ends  upon  poles  near  the 
ceiling  of  the  drying-room.  The  hides  are  left  suspend- 
ed in  this  way  until  three-quarters  dry.  They  are  then 
taken  down,  and  laid  out  upon  the  floor,  being  folded 
double,  with  the  hair  sides  within.  A  workman  stretches 
all  its  parts,  and  takes  out  the  wrinkles  which  have 
formed  in  it  by  forcibly  drawing  a  stick  two  feet  long 
and  about  two-thirds  of  an  inch  in  diameter  in  every 
direction  over  the  surfaces.  The  hides  are  then  piled, 
and  after  remaining  in  that  state  for  a  day  or  two,  are 
again  suspended  upon  the  poles,  and  thoroughly  dried. 

If  the  weather  be  cold  during  the  drying  process,  the 
hides  should  be  hung  for  a  time  on  the  poles  in  the  stove- 
room  before  described,  and  should  be  warmed  by  light- 
ing a  charcoal  fire  on  the  grate.  After  becoming  suffi- 
ciently warm,  they  may  be  stretched  and  piled  upon  one 
another,  and  should  in  that  case  be  covered  with  cloths 
to  protect  them  from  the  effects  of  the  cold.  Thus 
alumed  and  dried,  Hungary  leather  will  keep  as  well  as 
that  which  has  been  tanned,  and  it  is  only  necessary  to 
avoid  exposure  to  a  hot  sun  or  to  warm,  dry  winds,  in 
order  that  it  may  not  become  so  dry  as  to  be  worked 
afterwards  with  difficulty. 

6.  Treading  out  the  Hides. — The  leather  when  quite 
dry  is  softened,  and  prepared  for  receiving  the  tallow  by 
a  peculiar  method  of  stamping.  A  platform  (Fig.  124) 
is  erected,  consisting  of  planks,  slanting  in  one  direction, 


422  HUNGARY  LEATHER. 


Fig.  124. 


and  supported  upon  crosspieces  or  rafters  twelve  to  thir- 
teen inches  apart  from  each  other.  The  strip  of  hide  to 
be  worked  is  folded  doublCj  with  the  hair  side  in  contact; 
and  a  smooth  stick  of  hard  wood  (Fig.  125),  twenty-six 
inches  long  and  three-quarters  of  an  inch 
in  diameter  is  passed  through  it.  The 
workman,  having  his  feet  covered  with 
thick-soled  shoes  without  heels,  then  stands  upon  the 
folded  strip,  which  is  laid  upon  the  upper  part  of  the 
platform,  and  holding  on  to  a  railing  or  post,  proceeds 
to  roll  the  stick  by  repeated  stamping  and  shufEing 
movements  of  his  feet  from  its  first  position  to  the  edge 
of  the  strip.  This  is  repeated  again  and  again,  the 
position  of  the  stick  being  changed,  and  the  strip  of  hide 
being  turned  until  every  part  of  the  latter  is  well  tramped. 
The  leather  is  then  folded  in  the  opposite  direction,  so 
that  the  flesh  side  shall  be  in  contact,  and  is  exposed 
again  to  the  same  stamping  process.  The  operations 
should  be  continued  until  the  piece  becomes  as  soft  and 
supple  as  it  is  possible  to  make  it.  The  strips  of  hide 
are  then  piled  upon  each  other  for  a  time,  and  if  not 
sufficiently  dry  when  taken  down,  are  exposed  to  a  hot 
sun  or  to  the  heat  of  the  drying-room ;  after  which  they 


HUNGARY  LEATHER. 


423 


are  trodden  out  a  second  time,  precisely  in  the  same 
manner  as  before. 

7.  Tallowing  the  Hides. — The  strips  of  hide  are  im- 
pregnated with  suet  in  the  stove-room,  which  has  already 
been  described,  and  the  tallow  is  melted  in  a  boiler 
capable  of  containing  about  one  hundred  and  seventy 
pounds.  This  is  one  foot  eight  inches  deep,  and  two  feet 
three  inches  in  diameter,  and  is  imbedded  in  the  ma- 
sonry of  the  furnace  (Fig.  126)  . 

When  the  hides  are  ready  to  be  greased,  the  boiler  is 
three-quarters  filled  with  tallow,  and  is  heated  until  the 
latter  melts.  When  it  has  attained  a  degree  of  heat  a 
little  above  the  melting  point,  it  is  ready  for  use.  In 
the  event  of  the  heat  being  too  great,  and  of  the  boiling 
over  of  the  tallow,  the  draught  must  be  lessened,  and 
lumps  of  cold  tallow  must  be  thrown  in.  While  the 
tallow  is  being  melted,  a  fire  is  kindled  upon  the  grate, 
with  a  basket-full  of  charcoal.  The  basket  used  to  con- 
tain the  fuel  is  twenty-one  inches  in  height,  and  the 
same  in  diameter. 

As  soon  as  the  charcoal  is  kindled,  from  twenty-four 
to  thirty-eight  strips  of  hide,  according  to  their  size,  are 
folded  double,  and  then  stretched  across  the  poles  below 
the  ceiling  of  the  room,  the  largest  and  thickest  being 
placed  nearest  to  the  fire.  The  workmen  then  leave  the 
stove-room,  closing  the  door  tightly  behind  them,  in  order 
to  escape  from  the  stifling  vapors  proceeding  from  the 
hides,  and  the  noxious  carbonic  acid  from  the  charcoal, 
and  do  not  return  until  they  are  assured,  by  experience, 
that  the  heating  has  been  carried  far  enough.  They  then, 
after  airing  the  room  a  little  by  opening  the  door,  enter 
it  with  no  clothing  but  short  aprons,  and  proceed  to  exam- 
ine the  leather.  When  sufficiently  warmed,  a  white  ap- 
pearance, beginning  at  the  extremities,  and  extending 


424 


HUNGARY  LEATHER. 


over  the  whole  surface  of  the  hides,  is  observed.  As  soon 
as  this  is  the  case,  the  strips  are  removed  from  the  poles, 
and  stretched  out  upon  each  other,  with  the  flesh  side 
uppermost,  on  the  table  (Fig.  126)  near  the  boiler.  The 


Fig.  126. 


tail  or  thickest  parts  of  the  hides  are  placed  nearest  to 
the  boiler,  and  the  smallest  and  thinnest  strips,  or  those 
which  were  the  most  removed  from  the  fire  in  heating, 
are  made  to  occupy  the  lowest  position  in  the  pile. 

Two  workmen  are  employed  in  tallowing  the  hides. 
The  one  who  is  nearest  to  the  boiler,  takes  off  the  upper- 
most strip  of  the  pile,  and  folding  it  double,  with  the 
flesh  side  out,  and  the  head  placed  upon  the  tail,  assures 
himself  that  the  tallow  is  heated  to  the  proper  point. 
He  then  takes  a  tallowing  cloth  or  mop  (Fig.  127), 
made  with  pieces  of  woollen  rag  or  blanket- 
stuff,  a  foot  long,  and  tightly  tied  around  a 
wooden  handle  six  inches  in  length,  and  hav- 
ing immersed  it  in  the  boiler  long  enough  for  it 
to  become  saturated  with  the  melted  fat,  rubs  it 
over  the  head  part  of  the  flesh  side  until  that  half  of 
the  surface  is  sufficiently  fed. 

He  is  assisted  by  the  other  workmen  with  a  similar 
mop,  and  when  one-half  of  the  leather  is  properly 


Fiff.  127. 


HUNGARY  LEATHER. 


425 


greased^  it  is  extended  out  at  full  length  by  the  two 
workmen,  and  the  whole  of  the  flesh  side  is  saturated 
with  the  grease.  The  strip  is  then  turned  over,  and  the 
hair  side  is  greased  with  the  tallow  still  adhering  to  the 
mops,  which  are  not  dipped  again  in  the  boiler,  for  this 
purpose,  for  fear  of  injuring  the  surface  by  the  heat  of 
the  melted  tallow.  When  well  greased  throughout,  the 
strip  is  laid  out  upon  the  table  upon  the  opposite  side  of 
the  room,  with  the  flesh  side  up.  The  skins  are  in  like 
manner  successively  greased  and  piled  upon  each  other 
on  the  table,  until  the  end  of  the  operation. 

One  hour  is  usually  occupied  in  preparing  thirty  strips. 
Grease  of  an  inferior  quality,  such  as  the  residuum  of 
melted  tallow  and  kitchen  stuff"  may  be  employed,  and 
about  three  pounds  of  it-are  required  for  each  piece  of 
leather. 

It  is  probable  that  workmen  are  exposed  in  no  one  of 
the  arts,  to  more  fatigue  and  danger  than  they  are  com- 
pelled to  encounter  while  conducting  the  operations  of 
the  stove-room.  Constantly  inhaling  the  suffocating 
vapors  from  the  skins  and  the  melted  tallow,  and  the 
dangerous  carbonic  acid  given  off*  from  the  charcoal  fire, 
they  are  exposed  to  the  risk  of  suffocation,  or  at  least  to 
that  of  great  irritation  of  the  lungs ;  while  the  profuse 
flow  of  perspiration  from  the  whole  surface  of  the  body 
debilitates  and  predisposes  to  taking  cold.  Precautions 
should  be  taken  by  them  to  leave  the  room  as  soon  as 
the  charcoal  fire  is  lighted,  and  not  to  re-enter  it  until 
the  skins  are  sufficiently  warm,  and  until  the  atmosphere 
has  become  somewhat  changed  by  a  current  of  fresh  air 
entering  through  the  open  door.  The  workmen  should 
not  go  into  the  heated  apartment  with  full  stomachs,  but 
should  commence  the  operation  two  or  three  hours  after 
a  meal,  and  in  quitting  work,  should  immediately  leave 
28 


426 


HUNGARY  LEATHER. 


the  place,  and  rub  themselves  down  with  a  coarse  towel 
before  resuming  their  dress. 

Buzzing  or  tinkling  noises  in  the  ear,  giddiness,  and 
headache,  are  regarded  as  premonitors  of  the  dangerous 
effects  of  the  inhalation  of  carbonic  acid,  and  upon  the 
occurrence  of  these,  the  men  should  immediately  leave 
their  w^ork,  and  go  out  into  the  fresh  air.  The  most 
dangerous  part  of  this  process  might  be  entirely  avoided 
by  heating  the  stove-room  by  means  of  hot  air.  A  heat- 
ing apparatus  for  this  purpose  has  been  proposed  by  M. 
Curandeau.  It  consists  of  an  oval-shaped  stove,  two 
feet  high,  not  including  the  supports,  and  three  feet 
in  diameter.  The  interior  consists  of  a  cast-iron  hearth 
paved  at  the  bottom  with  bricks,  and  adapted  for  burning 
wood.  The  smoke  and  heat  ascend  through  a  pipe  two 
feet  long  and  five  inches  in  diameter,  and  are  conducted 
into  a  vertical  pipe  or  column,  three  feet  high  and  eleven 
inches  in  diameter.  From  the  top  of  this,  two  smaller 
pipes  diverge,  and  are  connected  with  two  other  vertical 
columns,  each  two  feet  ten  inches  in  height,  and  nine 
inches  in  diameter,  wdiich  are  placed  at  the  side  of  the 
main  column;  and  with  the  lower  ends  of  these  two 
pipes,  a  fourth  horizontal  one,  placed  two  inches  above  the 
top  of  the  stove  is  connected,  and  into  this  the  smoke  and 
heat  finally  enter,  the  former  to  escape  through  a  chim- 
ney, and  the  latter  to  be  given  off  to  the  air  of  the  room. 

8.  Flaming  the  Hides. — The  hides  are  left  for  a  time 
to  imbibe  the  tallow  with  which  they  have  been  impreg- 
nated, and  are  covered  with  cloths  in  order  to  prevent 
the  unequal  action  of  the  fire  upon  them.  A  fire  is  then 
kindled  upon  the  grating,  with  a  basket-full  of  charcoal ; 
the  workmen  leave  the  room,  and  after  about  a  half  an 
hour,  open  the  door  to  allow  the  escape  of  gas,  and  en- 
trance of  fresh  air.    The  charcoal  being  in  full  combus- 


HUNGARY  LEATHER. 


427 


tion,  two  workmen  then  enter,  and  taking  the  uppermost 
strip  off  the  pile,  one  by  the  head  and  the  other  by  the 
tail,  stretch  it  in  every  direction  over  the  fire,  with  the 
flesh  side  down,  and  continue  this  for  at  least  a  minute. 
The  strip  is  then  extended  upon  the  empty  table  with 
the  flesh  side  up,  and  the  same  process  is  repeated  with 
the  other  strips  of  the  pile.  When  the  flaming  (Fig. 
128)  is  finished,  the   newly  made   pile  of  hides  is 


Fig.  128. 


covered  over  with  cloth,  and  left  for  a  half  hour  in  sum^ 
mer,  and  three  hours  in  winter.  The  heat  to  which  the 
hides  are  exposed  in  this  flaming,  is  necessary  for  their 
complete  penetration  by  the  tallow ;  but  it  may  be  ap- 
plied in  a  diflerent  way.  Thus,  some  manufacturers 
light  a  large  fire  in  the  room,  and  keep  the  skins  exposed 
to  its  heat  with  the  door  closed  for  a  half  hour  or  more. 

9.  Exposure  to  the  Air. — After  the  hides  have  remained 
in  pile,  for  about  three-quarters  of  an  hour,  they  are 
wiped  upon  both  sides  with  a  dry  rag  or  mop,  in  order 
to  remove  the  excess  of  tallow,  and  are  then  hung 
upon  poles  in  the  air,  with  the  flesh  sides  up,,  and  the 
heads  and  tails  depending.  They  acquire  firmness  and 
consistency  by  this  exposure,  if  they  are  not  under  the 
direct  influence  of  the  sun's  rays.  If  prepared  in  sum- 
mer, they  should  be  tallowed  shortly  before  sundown,  so 


428 


HUNGARY  LEATHER. 


that  when  ready  to  be  aired  they  need  not  be  exposed 
to  the  heat,  but  may  be  cooled  by  the  night  air.  In 
winter  this  precaution  is,  of  course,  unnecessary.  Airing 
during  the  night  in  summer,  and  for  thirty  hours  in 
winter,  is  sufficient  to  prepare  the  hides  for  the  last 
operation. 

10.  Weigliing,  Marhing^  and  Piling, — The  hides  are 
weighed  after  the  airing  last  described,  and  most  of  them 
are  found  to  have  lost  nearly  one-half  of  their  original 
weight  in  the  operations  to  which  they  have  been  sub- 
jected, and  some  of  them  to  have  experienced  more  than 
that  amount  of  loss.  The  weight  of  each  strip  is 
marked  in  Roman  characters  upon  the  tail,  and  the 
hides  are  piled  up  in  a  place  which  is  neither  too  dry  nor 
too  moist;  and  after  remaining  thus  for  some  days  they 
are  in  a  proper  condition  to  be  delivered  to  the  harness- 
makers  or  other  consumers. 

Hungary  leather  can  be  prepared  for  the  market  in 
fifteen  days  in  summer,  and  in  three  weeks  or  a  month 
in  winter.  A  fine  strip  of  hide  weighs,  usually,  about 
thirty  pounds,  and  is  valued  at  about  forty  cents  the- 
230und. 

Hungary  Leather  made  of  Cow  and  Calf  Shins. — Cow- 
skins  are  occasionally  prepared  in  the  Hungarian  manner, 
but  they  are  deprived  of  hair  by  liming  instead  of  scrap- 
ing. They  are  left  in  the  lime-pits  for  eight  or  ten  days 
until  the  hair  is  ready  to  come  off.  It  is  then  removed, 
and  the  skins,  after  being  washed  and  scraped  until 
the  last  portions  of  lime  have  been  separated,  are  pre- 
pared exactly  in  the  same  manner  as  thick  hides,  ex- 
cepting that  they  are  not  exposed  for  so  long  a  time  to 
heat  in  the  stove-room,  before  being  tallowed.  Thej 
are  rendered  spongy  by  the  liming,  and  are  disposed  to 


HUNGARY  LEATHER. 


429 


absorb  a  larger  quantity  of  alum  and  salt  in  proportion 
to  their  weight,  than  ox-hides. 

Calf-skins  are  prepared  in  the  same  way,  but  absorb 
much  less  proportionate  quantities  of  the  materials  used. 
A  large  calf-skin  will  require  about  eighteen  ounces  of 
alum,  nine  ounces  of  salt,  and  a  pound  of  tallow. 

Hungary  Leather  made  of  Horse-Hides. — These  hides 
are  not  worked  when  dry,  but  are  taken  in  the  green 
state  ;  and  in  order  to  prevent  the  inequalities  of  surface 
which  would  otherwise  be  found  upon  them,  they  are 
not  thoroughly  fleshed,  but  a  part  of  the  membranous 
substances  is  left  upon  their  flesh  sides. 

They  are  first  cut  in  half  and  put  to  soak  for  twelve 
hours,  after  which  they  are  fleshed  with  a  sickle-shaped 
knife,  and  deprived  of  hair  by  liming,  first  in  an  old  pit 
for  one  day,  and  after  intervals  of  two  or  three  days, 
during  which  they  are  kept  piled  up,  in  a  second  and 
third  weak  lime-pit  for  three  days.  After  being  deprived 
of  hair,  they  are  soaked  for  twelve  hours  in  summer, 
and  twenty-four  in  winter,  with  occasional  stirring,  in 
order  to  remove  the  lime.  When  perfectly  clean,  they 
are  scraped  with  the  stone,  and  dressed  upon  the  hair 
side  with  the  round-knife.  They  are  then  rolled  up  from 
head  to  tail  and  put  aside  to  drain  for  six  hours. 

They  are  trodden  out  in  the  vats,  like  other  hides, 
with  three  alum-waters  only,  the  tails  and  manes  being 
beaten  more  forcibly  than  the  other  parts.  About  five 
and  a  half  pounds  of  alum,  and  two  and  three-quarter 
pounds  of  salt  are  required  to  impregnate  each  large 
horse-hide.  After  being  stamped,  they  are  placed  in 
the  tubs  with  alum-water,  and  remain  in  them  from  two 
to  eight  days,  and  are  then  tramped  upon  again  in  the 
same  liquors.  They  are  then  drained,  partially  dried, 
stretched  out  with  the  hands,  dried  entirely,  and  worked 


430 


HUNGARY  LEATHER. 


upon  the  platform  like  ox-hides ;  after  which,  they  are 
heated  upon  the  poles  of  the  stove-room,  for  from  a 
quarter  to  a  half  hour,  according  to  their  degree  of  dry- 
ness, and  when  thus  heated,  they  give  off  vapors  so 
offensive,  as  to  be  scarcely  endurable.  They  are  then 
tallowed  and  finished  in  the  ordinary  manner;  but  re- 
quire only  half  the  quantity  of  grease  which  is  used  for 
ox-hides. 

Hungary  leather  made  of  horse-hides,  is  often  mis- 
taken for,  and  sold  with  that  prepared  from  ox-hides; 
but  it  is  much  inferior  to  the  latter,  being  apt  to  harden 
and  shrink,  and  being  much  less  firm  and  strong. 

Hungary  Leather  jprepared  in  Imitation  of  Blachened 
Leather. — A  patent  was  taken  out  in  the  year  1836,  by 
Kresse,  for  the  following  method  of  preparing  black 
Hungary  leather: — 

The  hides  or  skins  intended  to  be  blackened,  are  taken 
when  fresh,  and  a  mixture  of  orpiment  and  lime,  with 
water,  is  spread  over  the  flesh  side  and  left  in  contact 
with  it  for  two  hours.  At  the  end  of  this  time,  the  hair 
is  taken  off,  and  the  skins  are  passed  during  some  days 
through  baths  of  tan,  alum,  and  salt.  They  are  then 
half  dried,  softened,  suppled,  and  dried.  After  being 
greased  with  boiling  tallow,  and  again  soaked  in  water, 
they  are  stretched  upon  the  table,  and  the  color  is  ap- 
plied upon  the  hair  side. 

The  surfaces  are  first  rubbed  over  twice  with  stale 
urine.  The  third  and  fourth  applications  consist  of  a 
color  made  with  decoctions  of  three  parts  of  logwood  and 
one  part  of  fustic,  and  the  fifth  and  sixth  of  alder  bark, 
iron  rust,  and  nutgalls,  mixed  with  lemon-juice.  After 
receiving  these  different  coatings,  the  skins  are  dried, 
and  smoothed  by  stretching  upon  the  table.  For  making 
the  color  of  the  last  two  applications,  100  spoiled  lemons 


HUNGARY  LEATHER. 


431 


are  squeezed  into  a  bucket-full  of  broken  pieces  of  aider 
bark,  mixed  with  ten  pounds  of  scraps  of  rusty  iron,  and 
one  pound  of  bruised  nutgalls.  The  contents  of  the 
bucket  are  stirred  up,  and  left  for  fifteen  days,  at  the 
end  of  which  time  the  liquid  is  poured  out,  and  is  ready 
for  use. 

The  skins  are  apt  to  become  mouldy  before  being 
colored,  if  piled  up  in  a  moist  place,  and  in  order  to  pre- 
vent this  occurrence  are  prepared  in  the  following  man- 
ner : — 

After  being  washed  in  the  river,  and  before  being 
alumed,  they  are  placed  in  a  vat,  and  covered  with 
warm  water,  with  which  a  bushel  of  bran  and  four 
ounces  of  ferment  for  each  skin,  have  been  previously 
mixed.  They  are  steeped  for  three  days  in  this  bath, 
and  are  afterwards  alumed,  and  trod  out  three  times  in 
warm  water,  to  remove  the  salt,  before  being  dried. 

In  order  to  give  the  skins  a  brown  color  similar  to 
that  of  tanned  leather,  after  being  tallowed,  they  are 
steeped  for  some  days  in  tan-liquor.  If  it  is  desired  to 
blacken  them,  they  may  then,  after  receiving  the  four 
first  dressings  mentioned  above,  be  brushed  over  twice 
on  the  hair  side  with  a  solution  of  copperas,  instead  of 
the  mixture  prepared  with  lemon-juice. 

CURANDEAU'S  PROCESS. 

Curandeau,  believing  that  the  change  experienced  by 
the  skins  in  the  saline  bath  is  due  chiefly  to  the  sulphu- 
ric acid  of  the  alum,  proposed  the  substitution  of  oil  of 
vitriol  for  that  salt.  The  skins,  after  passing  through 
the  preliminary  processes,  are,  when  treated  in  this  way, 
macerated  for  twenty-four  hours  in  a  bath  consisting  of 
twenty  pounds  of  salt  dissolved  in  twenty-five  gallons  of 


432 


HUNGARY  LEATHER. 


water,  and  mixed  with  four  pounds  of  sulphuric  acid  at 
66°.  They  are  then  taken  out,  dried,  and  finished  in 
the  ordinary  manner.  Curandeau  believes  that  as  much 
progress  is  made  by  the  skins  in  this  bath  in  twenty-four 
hours  as  by  those  which  are  exposed  for  a  much  longer 
time  to  alum  baths,  and  that  they  possess  all  the  best 
qualities  of  Hungary  leather.  The  advantages  of  the 
process  are,  that  the  same  bath  answers  for  numerous 
sets  of  hides,  the  loss  of  salt  and  acid  being  replaced 
each  time ;  the  superior  cheapness  of  the  acid,  and  the 
fact  that  the  necessity  of  heating  the  liquor,  and  of  work- 
ing the  skins  in  the  laborious  way  required  when  alum 
is  used,  is  avoided. 

Uses  of  Hungary  Leather  and  the  Causes  of  its  De- 
fects.— Hungary  leather  is  chiefly  employed  by  harness- 
makers  and  carriage-makers  for  different  parts  of  harness 
and  for  main-braces  of  coaches. 

Hides  of  the  best  quality,  as  recognized  by  the  signs 
which  have  already  been  described  in  treating  of  the 
tanner's  art,  should  alone  be  converted  into  Hungary 
leather.  Horse-hides,  intended  for  this  manufacture, 
should  be  taken  fresh  from  the  slaughter-house,  since 
even  the  commencement  of  putrefaction  will  diminish  or 
destroy  the  fineness  of  the  hair  side  to  which  this  leather 
owes  much  of  its  beauty  and  usefulness. 

Leather  which  has  been  imperfectly  tramped  during 
the  aluming  process,  or  which  has  only  been  treated  with 
two  or  three  waters,  cannot  be  properly  worked  upon 
the  platforms.  It  will  not  absorb  as  much  tallow  as  is 
necessary  for  it,  and  is  apt  to  contain  hard  and  horny 
portions  which  are  calculated  to  diminish  its  strength 
and  flexibility.  Those  hides  wjiich  have  spots  of  extra- 
vasated  blood  upon  their  surfaces,  should  be  rejected  as 
being  weak  and  of  bad  quality. 


CHAPTER  XXXVIII. 

OILED  LEATHER. 

Under  this  head  that  kind  of  leather  is  classed,  which 
is  distinguished  from  all  others  by  being  prepared  with- 
out tannin  or  alumina,  and  by  having  the  grain  surface 
of  the  skin  removed.  Fish  oil  is  the  preservative  sub- 
stance employed,  but  it  exerts  no  chemical  action  upon 
the  animal  tissue.  The  skins  are  made  to  imbibe  the 
oil  by  mechanical  force,  which  expels  and  volatilizes  the 
moisture  and  with  it  such  putrescent  matters  as  are 
soluble  in  cold  water.  All  tendency  to  decomposition  is 
thus  entirely  prevented. 

Oiled  leather  is  commonly  known  as  chamois ,  or  wash- 
leather.  It  derives  its  first  name  from  that  of  the  wild 
goat  of  the  Alps,  from  the  skins  of  which  it  was  origi- 
nally made;  and  the  last  from  its  property  of  bearing 
wetting  and  washing  without  suffering  injury.  It  is 
also  called  losh  leather.  In  former  times,  when  it  was 
generally  employed  as  material  for  the  clothing  of  the 
troops  and  peasantry  in  European  countries,  the  manu- 
facture was  very  extensive.  The  facility  with  which  it 
becomes  damp,  and  the  difiiculty  and  slowness  with 
which  it  dries,  together  with  the  chilling  effect  upon  the 
body,  and  consequent  injurious  influence  upon  the  health, 
have,  of  late  j^ears,  caused  its  disuse  for  that  purpose, 
and  materially  reduced  the  trade  in  the  article.    Its  use 


43^ 


OILED  LEATHER. 


is  now  almost  exclusively  limited  to  domestic  purposes, 
being  employed  chiefly  for  washing  and  polishing  furni- 
ture, &c. 

The  preliminary  preparations  of  this  leather  are  the 
same  as  for  tanning,  and  the  process  is  equally  appli- 
cable to  goat,  sheep,  lamb,  deer,  and  the  thin  sides  of 
split  skins ;  care  being  necessary,  however,  to  select  the 
finest  and  most  perfect. 

The  skins,  after  having  been  brought  to  the  state  of 
pelt  by  washing,  liming,  fleecing,  beaming,  and  branning, 
in  the  same  manner  as  for  kid  leather,  are  subjected 
to  what  is  technically  termed  frizing,  which  is  a  rubbing 
with  a  pumice  stone,  or  working  under  the  round  edge 
of  a  blunt  knife.  This  manipulation  removes  the  "  grain 
surface,"  equalizes  the  thickness  of  the  skin,  renders  it 
pliable,  and  exposes  a  softer  surface. 

The  skins  are  then  wrung  out,  transferred  to  the 
trough  of  a  fulling  mill  (Fig.  129),  and  subjected  to  the 


Fig.  129. 


OILED  LEATHER. 


435 


continuous  action  of  the  wooden  hammers  until  nearly 
dry,  when  they  must  be  removed,  spread  upon  the  table, 
and  severally  sprinkled  on  the  grain  side,  with  cod  or 
any  kind  of  fish  oil.  Being  now  folded  in  bundles  of 
four,  they  are  returned  to  the  trough,  and  beaten  as  be- 
fore, for  from  two  to  four  hours,  as  may  be  necessary  to 
produce  perfect  impregnation  with  the  oil,  after  which 
they  are  again  taken  out,  opened,  exposed  to  air  for  a 
short  time,  and  then  besmeared  with  grease,  and  fulled 
as  before.  These  manipulations  must  be  repeated  eight 
or  nine  times,  or  until  the  skins  become  thoroughly 
imbued  with  the  oil.  From  three  to  five  gallons  suffice 
for  one  gross  of  skins,  which  is  the  number  generally 
placed  in  the  trough  at  one  time. 

After  the  oil  has  been  well  beaten  into  the  pores  and 
there  is  no  appearance  of  greasiness,  the  skins  are  taken 
out,  and  suspended  by  hooks,  to  wooden  hangers  run- 
ning across  a  drying  chamber  about  six  feet  high  and 
twelve  feet  square,  kept  warm  by  steam-pipes,  or  the 
carefully  managed  heat  of  a  stove.  This  treatment 
causes  a  slight  fermentation  which  dilates  the  pores,  and 
promotes  the  intimate  incorporation  of  the  oil  with  the 
animal  fibre.  Moreover,  it  has  a  beneficial  influence  in 
destroying  any  remaining  decomposable  constituents  of 
the  skin. 

The  excess  of  oil  is  removed  by  immersing  and  hand- 
ling the  skins  for  an  hour  in  slightly  heated  potassa  lye, 
of  2°  Baume,  which  converts  it  into  soluble  soap.  They 
are  then  wrung  at  the  peg,  dried,  finished  first  on  the 
stretcher,  and  then  on  the  horsey  and  lastly  smoothed 
with  rollers. 

When  it  is  desired  to  impart  a  buff  color,  they  are 
merely  dipped  in  an  infusion  of  oak-bark,  which  in  this 
case  serves  as  a  dye,  and  not  as  a  tanning  stuff. 


436 


OILED  LEATHER. 


The  fulling  mill  used  in  this  manufacture  consists  of 
two  stocks,  the  head  covered  with  copper,  being  attached 
to  a  long  beam  or  handle  lying  in  an  inclined  position. 
Near  the  lower  end  of  each,  a  wheel  revolves,  by  which 
each  hammer  is  raised  and  dropped  through  a  space  of 
about  a  foot  into  the  trough  beneath.  The  upper  or 
handle  end  of  each  stock  is  adjusted  so  as  to  work  on  a 
pivot  or  axis;  and  the  stocks  being  set  in  action,  the  two 
descend  and  rise  alternately  at  regular  intervals,  and 
beat  the  skins  uniformly  until  they  are  perfectly  dry. 

nisbet's  process. 

Mr.  John  Nisbet,  of  England,  recommends  the  substi- 
tution of  machinery  for  the  hand  in  the  laborious  pro- 
cess of  grounding,  or  frizing,  and  has  invented  for  that 
purpose  a  very  ingeniously  constructed  apparatus.  He 
employs  knives  and  pumice  stones,  or  other  sufficiently 
rough  materials,  set  into  revolving  cylinders  which  are 
made  to  turn  in  contact  with  the  surfaces  of  leather. 
Fig.  130  represents  a  side  view;  and  Fig.  131  a  longitu- 

Fig.  130.  Fig.  13L 


dinal  section  of  one  of  these  machines ;  a  a,  framework ; 
Z),  axle  turning  in  the  supports  c  c,  and  made  to  revolve 
by  means  of  a  strap  around  the  pulley  d;  e  e,  series  of 
crosspieces,  or  arms,  each  of  which  is  provided  with  a 
paring-knife  /,  which,  by  the  revolution  of  the  shaft,  is 


OILED  LEATHER. 


437 


brought  ill  contact  with  and  made  to  pare  the  surface  of 
the  skin  or  portion  of  skin  placed  on  the  mattress  g. 
This  mattress  is  stuffed  with  hay  or  other  suitable  mate- 
rialj  and  is  covered  with  oiled  leather.  It  is  placed  upon 
the  top  or  table  of  a  car  mounted  on  four  grooved  wheels 
Ti  h,  which  run  on  the  railroad  i  i. 

The  arms  which  carry  the  knives  are  made  to  revolve 
at  least  360  times  in  a  minute^  and  the  rapidity  of  mo- 
tion can  be  increased  if  it  is  desirable  to  do  so. 

The  workman  places  the  skin,  or  portion  of  skin,  upon 
the  mattress,  and  pushes  the  car  forwards,  so  that  the 
end  of  the  piece  shall  be  under  one  of  the  series  of  blades. 
These  latter,  by  their  revolution,  then  draw  the  leather 
away  from  the  workman,  and  pare  its  surface  while  he 
retains  the  extremity  in  his  hands  and  retards  its  pro- 
gress more  or  less,  according  to  the  amount  of  action  to 
which  it  is  desired  to  expose  it.  When  one  side  is  thus 
pared  throughout,  the  band  is  slipped  off  from  the  pul- 
ley, so  as  to  stop  the  revolution  of  the  axle,  the  car  is 
'  drawn  back,  the  leather  turned,  and  the  strap  being  re- 
placed, the  other  side  is  made  to  undergo  the  same  treat- 
ment. Besides  great  rapidity,  this  operation  secures  a 
uniform  paring  of  the  leather. 

When  light  and  thin  skins  are  treated  in  this  manner, 


Fig.  132. 


438 


OILED  LEATHER. 


the  intervals  between  the  knives  are  filled  up  with 
wooden  blocks,  or  wedges,  so  that  the  axle  is  surrounded 
by  a  compact  cylinder  of  wood,  beyond  which  the  knives 
project  only  to  a  slight  extent.  Fig.  132  shows  the 
plan,  and  Fig.  133  the  side  view  of  the  machine  so  modi- 


Fig.  133. 


fied;  and  Figs.  134,  135,  136,  and  137,  exhibit  a  front 
view  of  the  arms  and  knives  from  between  which  the 
wooden  wedges  have  been  removed;  a  section;  a  side 
view;  and  front  view  of  the  series  of  knives  /,  and  of 
the  wedges/. 

Figs.  134.    135.  136.  137. 


Figs.  132  and  133  also  represent  the  apparatus  for 
pumici7ig  leather.  The  pumice  stones  ^,  or  other  suita- 
ble rough  substances,  are  attached  to  the  shafts  which 
are  made  to  revolve  by  the  ordinary  means.  In  other 
respects,  the  machine  resembles  the  preceding  one,  the 
same  letters  indicating  corresponding  parts  of  both. 

The  leather  submitted  to  the  action  of  this  machine, 
is  first  pared  by  means  of  two  sets  of  knives  /,  which 
are  represented  in  the  figure  as  turning  upon  two  shafts, 
and  it  then  passes  under  the  pumicing  cylinders,  which 
act  progressively  upon  every  part  of  the  surface.  Figs. 


OILED.  LEATHER. 


138,  139,  and  140  exhibit,  the  first  a  section,  the  second 

Figs.  138.  139.  140. 

1 


a  side  view,  and  the  third,  a  front  view  of  these  cylin- 
ders and  stones.    Figures  141  and  142  show,  the  one  a 


Fig.  141. 


cross  section,  and  the  other  a  longitudinal  section  of  the 
pumicing  machine  while  in  action. 


Fig.  142. 

□  


CHAPTEE  XXXIX. 


TANNING  AS  PRACTISED  BY  THE  CALMUCKS,  OR 
MONGOL  TARTARS. 

The  Calmiick  women  prepare  the  skins  of  young 
lambs  by  rinsing  them  in  warm  water,  stretching  and 
exposing  them  to  the  air  until  half  dry,  scraping  them 
upon  the  flesh  side,  and  again  partly  drying  them,  upon 
the  grass. 

They  then  rub  them  over  three  times  a  day,  for  three 
days,  with  sour  milk,  in  which  a  little  salt  has  been 
dissolved,  and  dry  them  upon  the  fourth  day,  working 
them  constantly  with  the  hands  and  over  the  knees, 
until  they  become  supple.  When  thicker  skins  are  pre- 
pared in  this  way,  they  are  softened  by  means  of  a  kind 
of  brake  with  grooved  edges. 

The  skins  are  then  smoked,  in  order  to  make  them 
impervious  to  water.  For  this  purpose,  a  fire  is  lighted 
in  the  bottom  of  a  small  pit,  and  rotten  wood,  dried 
dung,  pine  cones,  and  any  substances  which  produce  a 
thick  smoke  are  thrown  in  as  fuel.  Sticks  are  erected 
in  a  pyramidal  form  around  the  pit,  and  the  skins  are 
hung  thereon,  one  above  the  other,  their  position  being 
occasionally  changed,  so  that  those  which  are  under- 
neath at  first  are  placed  outside  in  their  turn.  This 
smoking  is  kept  up  for  an  hour  or  more ;  those  skins 
which  become  stiff  are  worked  to  render  them  pliable ; 


SKINS  PREPARED  BY  THE  TARTARS. 


441 


and  when  the  operation  is  concluded,  they  are  rubbed 
on  the  hair  side  with  chalk  or  powdered  gypsum,  scraped, 
whitened  again  with  chalk,  freed  from  hair,  and  beaten. 

Goat  or  sheep  skins,  intended  for  garments,  are  rolled 
up  when  fresh,  and  laid  aside  until  the  wool  detaches 
itself,  and  then  rubbed  with  sour  milk,  and  treated  in 
the  same  manner  as  lamb-skins.  They  are  finally 
rubbed  over  with  a  strong  decoction  of  statice  root,  with 
which  a  little  of  alum  and  mutton-suet  has  been  mixed ; 
dried,  and  rubbed  again  and  again  with  the  same  mix- 
ture, until  its  brownish-yellow  color  has  penetrated  the 
whole  skin.  These  skins  resist  moisture  exceedingly 
well. 

Those  of  the  Calmucks  who  are  engaged  in  the  Rus- 
sian fisheries,  make  the  skins  of  the  large  sea-carp  into 
garments  to  protect  them  from  the  rain.  They  dry  the 
skins,  remove  the  scales,  and  prepare  them  with  sour- 
milk,  or  a  decoction  of  statice  root. 

Their  hollow  utensils,  for  domestic  purposes,  are  all 
made  of  ox-hides  and  horse-hides.  These  are  boiled  in 
water  until  the  hair  can  be  readily  detached,  or  else 
are  deprived  of  it  by  means  of  ashes,  and  then  scraped 
and  rinsed  in  running  water  and  dried  in  the  sun.  Be- 
fore they  are  quite  dry,  they  are  cut  into  pieces,  sewed 
by  women  into  the  desired  form,  stretched  into  shape, 
and  smoke-dried.  These  vessels  retain  an  unpleasant 
odor,  and  easily  soften,  but  by  exposing  them  for  a 
number  of  days  to  a  thick  smoke,  they  acquire  almost 
the  transparency  of  horn,  and  become  so  firm  and  solid 
that  they  last  a  great  length  of  time. 


29 


442  SKINS  PREPAKED  BY  THE  INDIANS. 


TANNING  AS  PRACTISED  BY  THE  AMERICAN  INDIANS. 

The  following  method  was  communicated  to  the  Royal 
Society  of  London,  by  Sir  Robert  Southwell. 

As  soon  as  the  skin  is  removed  from  the  animal  by 
these  aboriginal  leather-dressers,  it  is  stretched  and 
dried.  The  brains  are  at  the  same  time  taken  out  and 
also  dried  upon  the  grass,  by  exposure  to  the  sun's  rays. 
When  the  season  of  the  chase  is  over,  the  squaws  soak 
these  skins  in  water,  remove  the  hair  from  them  with  an 
old  knife,  and  place  them  along  with  the  brains,  in  a 
large  earthen  pot;  the  contents  are  then  heated  to  about 
95°,  which  converts  the  moistened  brains  into  a  kind  of 
lather,  and  makes  the  skins  exceedingly  clean  and 
pliable.  They  are  then  taken  from  the  pot,  wrung  out, 
and  stretched  in  every  direction,  by  means  of  thongs,  over 
a  frame  composed  of  upright  stakes  and  crosspieces; 
and  while  drying  they  are  constantly  rubbed  with  a 
smooth  stone,  or  hard  rounded  piece  of  w^ood,  so  as  to 
expel  the  water  and  fat.  One  squaw  can  prepare  eight 
or  ten  skins  in  a  day. 


CHAPTER  XL. 


SHAGREEN. 

Genuine  shcagreen  of  the  best  quality  is  manufactured 
almost  entirely  in  Astracan  and  other  parts  of  Asiatic 
Russia,  where  it  is"  prepared  by  the  Tartars  and  Rus- 
sians. Fine  gray  shagreen,  as  well  as  that  of  other 
colors,  is  imported  from  Constantinople,  and  the  white 
of  a  good  quality  is  obtained  from  Algiers  and  Tunis. 
A  very  inferior  article  is  also  manufactured  in  Poland. 
The  genuine  oriental  shagreen  is  not  a  true  leather,  but 
a  skin  prepared  by  drying,  and  without  the  chemical 
action  of  any  tanning  material. 

The  particulars  of  the  manufacture  of  shagreen  have 
not  been  ascertained  with  certainty,  but  the  following 
process  is  that  which  is  said  to  be  pursued  in  Astracan. 

The  skins  of  horses,  asses,  and  camels  are  the  exclu- 
sive raw  material ;  and  only  the  small  strip  from  the 
crupper  along  the  chine  to  the  neck,  can  be  employed. 
This  is  cut  off  just  above  the  tail,  in  a  semicircular  form, 
about  thirty-four  inches  upon  the  crupper,  and  twenty- 
eight  along  the  back.  These  strips  are  soaked  in  water, 
until  the  hair  is  ready  to  come  off,  when  it  is  separated 
by  scraping;  and  the  pieces,  after  being  again  steeped, 
are  dressed  with  the  fleshing-knife  until  all  the  extraneous 
matter  is  removed,  and  they  have  been  reduced  to  the 
thinness  of  a  hog's-bladder.  They  are  then  stretched 
tightly  across  frames,  and  occasionally  dampened  to  pre- 


444 


SHAGREEN. 


vent  them  from  shrinking  unequally ;  after  which,  they 
are  laid  on  the  floor,  with  the  flesh  sides  undermost,  and 
the  grain  sides  are  then  thickly  strewed  over  with  the 
smooth,  hard  seeds  of  the  alabuta,  or  goose-foot  {cJienopo- 
dium  album).  Instead  of  these,  mustard  seeds  are  used 
in  some  places.  A  felt  is  then  laid  over  the  whole,  and 
the  seeds  are  forced  deeply  into  the  soft  moist  skins  by 
treading  upon  them,  or  by  the  action  of  a  press.  The 
characteristic  mottled  or  granular  appearance  of  the  hair 
side  of  shagreen  is  given  to  it  by  this  operation. 

The  frames,  with  the  seeds  sticking  in  the  skins,  are 
then  dried  slowly  in  the  shade,  until  the  seeds  are  ready 
to  drop  off  upon  shaking;  and  the  skins,  which  are  thus 
converted  into  hard,  horny  membranes  with  the  surfaces 
deeply  indented,  are  laid  upon  a  block  or  beam,  padded 
with  wool,  and  are  shaved  down  until  the  depressions 
caused  by  the  seeds  become  very  slight  and  uniform. 
The  skins  are  steeped  first  in  water,  and  afterwards  in 
a  warm  alkaline  lye,  and  are  piled  upon  each  other  while 
still  warm  and  moist.  By  this  means,  the  parts  indented 
by  the  pressure  of  the  seeds  regain  their  natural  elas- 
ticity, and,  not  having  lost  substance  by  the  shaving  of 
the  rest  of  the  skins,  they  rise  to  or  above  the  surround- 
ing level,  and  form  the  peculiar  grain  of  the  shagreen. 
After  this,  the  skins  are  cleansed  by  salt  brine,  and  dyed. 

The  beautiful  green  dye  is  given  to  shagreen  by  pass- 
ing a  concentrated  solution  of  sal-ammoniac  over  the  flesh 
side,  strewing  it  over  with  copper  filings,  rolling  it  up 
with  the  same  side  inwards,  and  pressing  each  skin  for 
twenty-four  hours  with  a  heavy  weight.  The  sal-am- 
moniac dissolves  enough  of  the  copper  to  give  the  skin 
a  beautiful  sea-green  color. 

Blue  shagreen  is  dyed  with  indigo  dissolved  in  a  solu- 
tion of  soda,  with  lime  and  honey ;  the  black,  with  nutgalls 


SHAGREEN. 


445 


and  copperas;  and  the  red,  with  decoction  of  cochineal. 
Pure  white  shagreen  is  made  by  dressing  the  strips  first 
with  alum  solution,  and  then  with  wheat  dough,  and 
washing  away  the  latter  with  alum  water.  Greasing, 
careful  working  in  hot  water,  currying  with  a  blunt 
knife,  and  drying,  complete  the  preparation. 

Shagreen  is  rendered  very  hard  by  drying,  but,  like 
parchment,  it  softens  in  water,  and  in  that  state  will 
take  any  shape  given  to  it,  and  is  used  by  sheath-makers 
for  the  cases  of  spectacles,  lancets,  mathematical  instru- 
ments, &c. 

There  is  an  imitation  shagreen  which  is  so  much  like 
the  genuine  article  that  it  is  almost  impossible  to  distin- 
guish the  difference.  For  the  purpose  of  manufacturing 
this  article,  sheep  or  goatskins,  after  being  deprived  of 
hair  in  the  lime-pits,  are  steeped  in  water,  fleshed,  soaked 
again,  and  well  rubbed  down  upon  the  horse  with  a  hard, 
polished  piece  of  wood,  after  which  they  are  steeped  a 
third  time,  and  beaten  out  and  trimmed  on  both  sides. 
They  are  then  steeped  for  two  hours  in  a  bath  made  of 
a  bucket-full  of  tan  for  every  fifty  skins,  mixed  with 
water  enough  to  cover  them;  a  bucket  half  full  of  the 
same  being  thrown  in  at  the  end  of  an  hour,  and  another 
at  the  end  of  an  hour  and  a  half.  After  this,  they  are 
kept  in  tan-pits  for  eight  days,  and,  when  removed  from 
them,  are  wrung  out,  and  reduced  in  thickness  by  the 
use  of  the  round-knife  applied  upon  the  horse.  They 
are  then  half-dried,  well  stretched  in  the  direction  of 
their  length,  cut  in  half,  blackened  in  the  ordinary  man- 
ner and  dried. 

The  grain  is  given  to  this  false  shagreen  by  means  of 
copper  plates  which  have  been  engraved  in  imitation  of 
the  roughened  surface  of  the  real  article.  These  plates, 
previously  warmed,  are  placed  upon  the  skins,  and  then 
subjected  to  the  action  of  a  press. 


CHAPTER  XLI. 


PARCHMENT. 

Parchment  is  the  invention  of  Eumenes,  king  of 
Pergamus,  in  Asiatic  Turkey,  about  200  years  before 
Christ.  It  was  known  in  early  times,  as  Pergamena^  and 
was  used,  on  account  of  its  great  durability,  for  records 
and  valuable  manuscripts,  and  as  a  substitute  for  the 
fapjrus^  or  writing-paper  of  the  ancient  Egyptians.  The 
finest  quality,  made  from  thin  and  perfect  skins,  and 
prepared  by  very  careful  manipulation,  is  called  vellum. 

Fine  parchment,  for  writings,  is  made  from  the  skins 
of  calves,  kids,  stillborn  lambs,  sheep,  and  she-goats; 
but  an  inferior  quality,  for  drum-heads  and  battledores, 
is  prepared  from  the  skins  of  he-goats,  calves,  wolves, 
and  asses.  Pig-skin  is  also  sometimes  converted  into 
parchment  for  bookbinders'  use.  The  operations  are 
nearly  the  same,  throughout,  for  all  the  varieties,  but 
are  more  delicate  for  the  finer  quality. 

The  skins  above  mentioned  are  those  generally  em- 
ployed for  this  branch  of  manufacture,  but  all  other  thin 
skins  are  applicable;  and  sometimes  the  thinner  halves 
of  thick  hides,  split  by  machinery,  are  dressed  by  this 
process. 

"The  skins,  after  having  been  soaked,  limed,  shaved, 
and  well  washed,  must  be  set  to  dry  in  such  a  way  as  to 
prevent  their  puckering,  and  to  render  them  easily 


PARCHMENT. 


447 


worked.  The  small  manufacturers  make  use  of  hoops 
for  this  purpose,  but  the  greater  employ  a  horse,  or  stout 
wooden  frame.  This  is  formed  of  two  uprights  and  two 
crossbars,  solidly  joined  together  by  tenons  and  mortises, 
so  as  to  form  a  strong  piece  of  carpentry,  which  is  to  be 
fixed  against  a  wall.  These  four  bars  are  perforated 
throughout  with  a  series  of  holes,  which  are  fitted  with 
very  smooth  and  slightly  tapered  box-wood  pins.  Each 
of  these  pins  is  transpierced  with  a  hole  like  a  violin 
screw,  by  means  of  which  the  strings  used  in  stretching 
the  skin  may  be  tightened.  Above  the  horse,  there  is  a 
shelf  for  such  tools  as  the  workman  may  need  at  hand. 
In  order  to  stretch  the  skin  upon  the  frame,  large  or 
small  skewers  are  employed,  according  to  the  size  of 
the  piece  which  is  to  be  attached  to  it.  Six  holes  are 
made  in  a  straight  line  to  receive  the  larger,  and  four  to 
receive  the  smaller  skewers,  or  pins.  These  small  slits  are 
made  with  a  tool  like  a  carpenter's  chisel,  and  of  the 
exact  size  to  admit  the  skewers.  The  string  round  the 
skewer  is  affixed  to  one  of  the  bolts  in  the  frame,  which 
is  turned  round  by  means  of  a  key,  like  that  by  which 
harps  and  pianos  are  tuned.  The  skewer  is  threaded 
through  the  skin  when  in  a  state  of  tension. 

"Everything  being  thus  prepared,  and  the  skin  being 
well  softened,  the  workman  stretches  it  powerfully,  by 
means  of  the  skewers;  he  attaches  the  cords  to  the 
skewers,  and  fixes  their  ends  to  the  iron  pegs,  or  pins. 
He  then  stretches  the  skin,  first  with  his  hand  applied 
to  the  pins,  and  afterwards  with  the  key.  Great  care 
must  be  taken  that  no  wrinkles  are  formed.  The  skin 
is  usually  stretched  more  in  length  than  in  breadth,  from 
the  custom  of  the  trade;  though  extension  in  breadth 
would  be  preferable,  in  order  to  reduce  the  thickness  of 
the  part  opposite  the  back  bone. 


448 


PARCHMENT. 


"The  workman  now  takes  the  fleshing-toolj  which  is 
a  semi-circular  double-edged  knife,  made  fast  into  a 
double  wooden  handle,  seizes  it  in  his  two  hands  so  as  to 
place  the  edge  perpendicularly  to  the  skin,  and  pressing 
it  carefully  from  above  downwards,  removes  the  fleshy 
excrescences,  and  lays  them  aside  for  making  glue.  He 
now  turns  round  the  horse  upon  the  wall,  in  order  to  get 
access  to  the  outside  of  the  skin,  and  to  scrape  it  with 
the  tool  inverted,  so  as  to  run  no  risk  of  cutting  the 
epidermis.  He  thus  removes  any  adhering  filth,  and 
squeezes  out  some  water.  The  skin  must  next  be  ground. 
For  this  purpose,  it  is  sprinkled  upon  the  fleshy  side 
with  sifted  chalk  or  slaked  lime,  and  then  rubbed  in  all 
directions  with  a  piece  of  pumice-stone,  four  or  five 
inches  in  area,  previously  flattened  upon  a  sandstone. 
The  lime  soon  becomes  moist  from  the  water  contained  in 
the  skin.  The  pumice-stone  is  then  rubbed  over  the 
other  side  of  the  skin,  but  without  chalk  or  lime.  This 
operation  is  necessary  only  for  the  best  parchment  or 
vellum.  The  skin  is  now  allowed  to  dry  upon  the  frame, 
being  carefully  protected  from  sunshine  and  from  frost. 
In  the  warm  weather  of  summer,  a  moist  cloth  needs  to 
be  applied  to  it  from  time  to  time,  to  prevent  its  drying 
too  suddenly;  immediately  after  which,  the  skewers 
require  to  be  tightened. 

"  When  it  is  perfectly  dry,  the  white  color  is  to  be  re- 
moved by  rubbing  it  with  the  woolly  side  of  a  lamb-skin. 
But  great  care  must  be  taken  not  to  fray  the  surface ;  a 
circumstance  of  which  some  manufacturers  are  so  much 
afraid  as  not  to  use  either  chalk  or  lime  in  the  polishing. 
Should  any  grease  be  detected  upon  it,  it  must  be  re- 
moved by  immersion  in  a  lime-pit  for  ten  days,  and  by 
then  stretching  it  anew  upon  the  liorse^  after  which  it  is 
transferred  to  the  scrapper. 


PARCHMENT. 


449 


"  This  workman  employs  here  an  edge  tool  of  the  same 
shape  as  the  fleshing-knife,  but  larger  and  sharper.  He 
mounts  the  skins  upon  a  frame  like  the  horse  above  de- 
scribed; but  he  extends  it  merely  with  cords,  without 
skewers,  or  pins,  and  supports  it  generally  upon  a  piece 
of  raw  calf-skin,  strongly  stretched.  The  tail  of  the  skin 
being  placed  towards  the  bottom  of  the  frame,  the  work- 
man first  pares  off,  with  a  sharp  knife,  any  considerable 
roughnesses,  and  then  scrapes  the  outside  surface  oblique- 
ly downwards  with  the  proper  tools,  till  it  becomes  per- 
fectly smooth.  The  fleshy  side  needs  no  such  operation, 
and,  indeed,  were  both  sides  scraped,  the  skin  would  be 
apt  to  become  too  thin,  the  only  object  of  the  scraper 
being  to  equalize  its  thickness.  Whatever  irregularities 
remain,  may  be  removed  with  a  piece  of  the  finest  pum- 
ice-stone, well  flattened  previously,  upon  a  piece  of  close- 
grained  sandstone.  This  process  is  performed  by  laying 
the  rough  parchment  upon  an  oblong  plank  of  wood,  in 
the  form  of  a  stool;  the  plank  being  covered  with  a 
piece  of  soft  parchment  stufied  with  wool,  to  form  an 
elastic  cushion  for  the  grinding  operation.  It  is  merely 
the  outside  surface  that  requires  to  be  pumiced.  The 
celebrated  Strasburg  vellum  is  prepared  with  remarka- 
bly fine  pumice-stones. 

"  If  any  small  holes  happen  to  be  made  in  the  parch- 
ment, they  must  be  neatly  patched,  by  cutting  their 
edges  thin  and  pasting  on  small  pieces  with  gum-water. 

Parchment  is  colored  only  green.  Boil  8  parts  of 
cream  of  tartar  and  30  parts  of  crystallized  verdigris  in 
500  parts  of  rain-water ;  and,  when  this  solution  is  cold, 
pour  into  it  4  parts  of  nitric  acid.  Moisten  the  parch- 
ment with  a  brush,  and  then  apply  the  above  liquid  even- 
ly over  its  surface.  Lastly,  the  necessary  lustre  may 
be  given  with  white  of  eggs,  or  mucilage  of  gum  Arabic." 


CHAPTER  XLII. 

LEATHER  BOTTLES. 

In  some  of  the  southern  districts  of  France,  leather 
bottles  are  very  important  objects  of  manufacture,  as 
they  are  in  general  use  for  carrying  oil  and  wine.  Cow- 
skins  are  used  for  the  purpose,  and  those  from  Mezin, 
and  the  mountains  near  Puy,  are  said  to  be  the  only 
ones  fit  for  the  manufacture.  They  are  carefully  dried 
upon  pegs  by  the  butchers,  and  are  then  softened  in  lime 
which  has  already  been  used,  and  in  which  they  remain 
for  eight  days.  They  are  then  thrown  into  a  fresh  lime- 
pit,  until  the  hair  readily  comes  off,  are  cleaned,  rinsed 
and  fleshed,  after  having  been  cut  into  pieces  of  the 
proper  shape.  They  are  now  exposed  to  dry  upon  a 
smooth,  clean,  and  dry  spot  of  ground,  great  care  being 
observed  that  this  drying  takes  place  uniformly  and  very 
gradually,  the  rays  of  the  sun  and  any  excess  of  heat 
being  prevented  from  affecting  them.  Having  thus  been 
deprived  of  moisture,  at  the  same  time  that  they  preserve 
all  their  suppleness,  they  are  hung  up  for  a  month  and 
exposed  to  the  direct  rays  of  the  sun,  being  taken  down 
and  stored  at  night,  so  that  no  moisture  shall  have  access 
to  them. 

Before  being  sewed,  they  are  placed  in  water  to  allow 
the  stitches  to  be  made.    These  bottles  last  a  long  time. 


LEATHER  BOTTLES. 


451 


but  liquids  kept  in  them,  nearly  always  acquire  an  un- 
pleasant taste. 

TANNING  OF  THE  SKINS  OF*SHEEP'S  LEGS,  FOR  MAKING  TUBES 
WITHOUT  SUTURE,  FOR  COVERING  THE  CYLINDERS  USED  IN 
COTTON  AND  WOOL  SPINNING. 

Delvau,  a  Parisian  tanner,  took  out  a  patent  of  inven- 
tion for  this  purpose,  which  is  described  in  Vol.  lY.  p. 
296,  of  Expired  Patent  Reports.  His  process  consists 
in  cutting  the  skin  of  the  sheep's-foot  circularly  above 
the  spur,  and  stripping  it  off  in  a  manner  similar  to  that 
after  which  rabbits  are  uncased.  This  tube,  thus  made, 
is  then  limed  until  the  wool  falls  off,  is  daubed  with 
oil,  and  curried  so  as  to  make  it  of  an  equal  thickness 
throughout. 

To  apply  the  leather  tubes  upon  the  cylinders  without 
suture,  two  burnishing  tools  are  used  for  spreading  them 
out.  Each  tube,  which  is  made  of  such  a  size  as  to  ex- 
ceed the  cylinder  a  little  in  diameter,  is  then  drawn  over 
it,  and  stretched  upon  it  by  means  of  pincers,  and  the 
parts  which  pass  beyond  the  ends  of  the  cylinder  are 
folded  down,  smoothed  out,  and  glued  over  them.  These 
extremities  are  then  rubbed  with  the  burnishers,  in  order 
to  make  the  glue  enter  the  substance  of  the  leather,  and 
they  are  left  to  dry  for  five  or  six  hours.  The  shreds  of 
leather  are  then  removed,  and  those  parts  which  project 
from  the  middle  and  ends  are  cut  away  on  a  turning 
lathe.  To  finish  the  surface,  and  give  it  lustre,  it  is 
then  well  rubbed  with  a  hard  linen  cloth. 


CHAPTEE  XLIII. 


ENGLISH  PROCESS  FOR  TANNING  NETS,  SAILS,  AND 
CORDAGE. 

A  SHIP-BUILDER  of  Bridgeport  has  proposed  the  follow- 
ing method  of  preserving  and  increasing  the  strength  of 
nets,  sails,  and  cordage.  A  hundred  pounds  of  oak 
branches  and  the  same  quantity  of  tan  are  boiled  in 
89  gallons  of  water,  until  it  is  reduced  to  seventy-one 
gallons.  The  solid  materials  are  then  taken  out,  and 
the  articles  to  be  tanned  are  deposited  in  the  liquid,  care 
being  taken  that  they  are  entirely  covered  by  it,  and  do 
not  rest  upon  the  bottom  of  the  vessel.  They  are  boiled 
for  three  hours,  and  are  then  taken  out  and  dried. 

This,  though  a  true  tanning  process,  can  scarcely  be 
likened  to  the  ordinary  ones  for  preparing  leather,  since  its 
object  is  a  combination  of  tannin  and  extractive  matter 
with  vegetable  substances,  which  are  very  different  from 
the  gelatine  of  skin.  According  to  Millet,  linen  which 
had  been  steeped  in  an  oak-bark  liquor  at  150°  F.  for 
two  or  three  days,  remained  unaltered  in  a  damp  cellar 
for  ten  years,  while  an  untanned  piece  entirely  rotted 
under  similar  circumstances. 


CHAPTER  XLIV. 


GLAZED,  OR  VARNISHED  LEATHER. 

This  leather,  known  in  commerce  as  patent  leather,  is 
very  largely  used  for  dress  boots  and  shoes,  and  for  fancy 
mountings.  There  are  various  methods  of  manufactur- 
ing it,  but  the  following  are  those  most  generally  em- 
ployed : — 

Two  distinct  operations  are  resorted  to  in  the  manu- 
facture of  polished  leather,  one  of  which  is  the  prepara- 
tion of  the  surface  for  receiving  the  varnish,  and  which 
is  effected  by  closing  the  pores  of  the  leather,  and  mak- 
ing a  proper  ground  by  repeatedly  rubbing  the  surface 
with  pulverulent  substances,  and  incorporating  them 
with  it;  and  the  other  is  the  varnishing  of  the  leather 
thus  dressed  with  suitable  brilliant  and  transparent 
materials. 

The  basis  or  medium  of  the  substances  used  for  both 
these  purposes  is  linseed  oil,  made  drying  by  boiling  with 
metallic  oxides  or  salts,  and  reduced  to  a  syrupy  con- 
sistence by  the  prolonged  action  of  heat. 

Five  gallons  of  linseed  oil  are  boiled  with  four  pounds 
four  and  a  half  ounces  of  white  lead,  and  the  same  quan- 
tity of  litharge,  each  in  a  state  of  fine  division,  until  it 
becomes  of  the  consistence  of  thick  syrup.  This  mix- 
ture is  then  intimately  united  wdth  one  of  the  ochres,  or 
with  powdered  chalk,  according  to  the  fineness  of  the 


454  GLAZEDj  OR  VARNISHED  LEATHER. 


skins  which  are  to  be  prepared,  and  is  uniformly  spread 
upon  either  side  of  the  leather,  and  well  worked  into  the 
pores  with  appropriate  tools.  Three  very  thin  coats  of 
it  are  applied  in  the  same  manner,  at  sufficiently  long 
intervals  to  enable  them  to  dry  between  the  different 
applications,  and  the  surface  is  then  forcibly  and  uni- 
formly rubbed  with  pumice-stone.  A  number  of  thin 
coatings  of  the  preparation  are  then  applied  in  a  similar 
manner,  and  rubbed  down  as  before  until  perfectly  uni- 
form, and  of  a  sufficient  thickness  to  prevent  the  varnish 
from  penetrating  the  leather,  by  which  its  quality  would 
be  injured,  and  its  structure  rendered  hard  and  brittle. 
The  oily  substance  of  the  preparation  and  of  the  varnish 
should  merely  penetrate  deeply  enough  into  the  leather 
to  make  the  compositions  of  which  it  is  the  basis  adhere 
closely  to  it. 

The  foundation  for  the  varnished  surface  being  thus 
laid,  a  mixture  of  the  preparation  before  used,  without, 
however,  the  addition  of  ochreous  or  other  earthy  mat- 
ters, and  well  rubbed  up  with  fine  ivory-black  and  enough 
spirits  of  turpentine  to  make  it  flow  smoothly  and  easily, 
is  laid  on  by  means  of  a  fine  brush ;  three  or  four  succes- 
sive coatings  being  applied.  By  this  means,  a  black  and 
shining  pliable  surface  is  obtained,  over  which,  as  soon 
as  it  is  perfectly  dry,  the  varnish  may  be  applied. 

The  leather  is  dried  after  the  application  of  each  coat, 
by  hanging  it  up,  or,  what  is  better,  laying  it  out  upon 
frames  or  racks  in  the  drying-room.  It  is  customary 
before  the  varnishing,  to  give  a  polish  to  the  surface  by 
rubbing  it  over  with  a  piece  of  woollen  stuff  and  the 
finest  kind  of  pumice  powder  or  tripoli. 

The  varnish  is  composed  of  one  pound  either  of  as- 
phalte,  Prussian  blue,  or  fine  ivory-black,  ten  pounds  of 
thick  copal  varnish,  twenty  pounds  of  the  linseed  oil 


GLAZED,  OR  TARNISHED  LEATHER. 


455 


prepared  as  before  described  by  boiling  with  litharge 
and  lead,  and  of  twenty  pounds  of  spirits  of  turpentine. 
The  asphalte,  Prussian  blue,  or  ivory-black,  in  the  finest 
possible  state  of  division,  is  first  thoroughly  mixed  with 
the  oil,  and  they  are  then  heated  together.  The  varnish 
first  and  then  the  turpentine  are  each  gradually  added 
with  constant  stirring,  until  a  homogeneous  mixture  is  ob- 
tained. This  is  not  ready  for  immediate  use,  but  must 
be  kept  covered  in  a  warm  place  during  two  or  three 
weeks,  at  the  end  of  which  tipie  the  proper  number  of 
coatings  are  applied  to  the  leather  with  a  fine  brush. 

The  drying-room  is  maintained  at  a  temperature  of 
from  132°  to  167°  Fahrenheit;  and  the  greatest  care 
must  be  taken  that  it,  as  well  as  the  apartments  in  which 
the  skins  are  covered  with  the  preparation  and  the  var- 
nish, be  perfectly  tight,  clean,  and  free  from  particles  of 
floating  dust. 

The  tint  of  color  of  polished  leather  varies  with  the 
coloring  material  which  has  been  added  to  the  varnish ; 
asphalte  giving  the  surface  a  reddish  hue,  Prussian  blue 
a  greenish-blue  metallic  tint,  and  the  ivory-black,  which 
is  most  commonly  employed,  a  pure,  brilliant  black 
lustre. 

Some  manufacturers  add  to  the  litharge  employed  for 
thickening  the  oil,  red-lead,  ceruse,  powdered  cuttlefish 
bone,  oxides  of  manganese,  and  various  other  metallic 
oxides  and  salts. 

The  success  of  the  whole  process  depends  very  much 
upon  the  care  with  which  the  skins  prepared  with  it  have 
been  selected,  tanned,  and  curried.  It  is  particularly 
necessary  that  the  dubbing  should  have  been  applied  to 
them  with  great  uniformity,  and  only  in  small  quanti- 
ties, for  otherwise  the  surfaces  will  soon  became  tar- 
nished and  blotted. 


456 


GLAZED,  OR  TARNISHED  LEATHER. 


didier's  process. 

In  this  process,  lampblack  is  heated  in  a  closed  vessel, 
and  is  mixed  with  linseed-oil  varnish  until  the  mass  be- 
comes sufficiently  liquid  to  flow.  Two  coatings  of  this 
mixture  are  applied  to  the  leather,  which  is  then  dried, 
and  coated  with  a  mixture  of  equal  parts  of  the  first 
liquid  and  of  copal  varnish.  As  soon  as  this  is  dry,  it 
is  polished  with  a  piece  of  felt  charged  with  finely  pow- 
dered pumice-stone,  and  is  then  rubbed  with  a  waxed 
sponge,  and  wiped  with  a  cloth. 

The  polish  consists  of  five  or  six  coatings  of  lamp- 
black and  varnish,  mixed  and  brought  to  the  proper  con- 
sistence by  means  of  a  slab  and  muller,  and  laid  on  with 
a  brush.  When  dry,  the  surface  is  again  smoothed  as 
before,  with  the  addition  of  friction  with  finely  pulve- 
rized bone-dust,  after  which  two  more  coatings  of  the 
varnish  are  applied. 

White  Polished  Leather, — White  lead  is  brought  to  the 
proper  consistence  with  white  oil  varnish,  and  two  coats 
of  this  are  applied  to  the  leather.  A  quantity  of  Krem's 
white  is  then  intimately  mixed  with  water;  the  water  is 
evaporated,  and  the  powder  is  incorporated  with  white 
copal  varnish.  Three  or  four  coats  of  this  mixture  are 
then  applied,  and  when  dry,  the  surface  is  polished  in  the 
manner  already  described. 

Red  Polished  Leather. — The  first  coating  consists  of 
shell-lac  ground  in  oil  of  turpentine ;  the  second  of  shell- 
lac  mixed  with  copal  varnish ;  the  last  is  prepared  by  dis- 
solving one  part  of  gum  copal  in  two  parts  of  oil  of  tur- 
pentine, and  adding  to  this  solution  an  equal  quantity  of 
linseed-oil  varnish. 

Blue  Polished  Leather, — A  coat  of  white  lead  incorpo- 


GLAZED,  OR  VARNISHED  LEATHER. 


457 


rated  with  oil  varnish  is  first  applied,  and  then  one  of 
Prussian  blue  and  copal  varnish.  If  a  lighter  blue  color 
is  desired,  a  little  Krem's  white  is  added  to  the  mixture. 

Yellow  Polished  Leather. — A  mixture  of  fustic  wood, 
cochineal,  alum,  and  of  an  alkaline  lye  is  boiled  in  a  cop- 
per vessel.  This  solution  is  applied  by  means  of  a  cloth 
to  the  leather,  and  when  the  latter  is  dry,  a  coat  of  copal 
varnish  is  laid  on  it. 

A  mixture  of  yellow-ochre,  white  lead,  and  ordinary 
varnish  is  then  applied,  and  a  second  coat  of  the  same 
mixed  with  copal  varnish  is  laid  on.  When  the  surface 
is  dry,  it  is  polished,  and  then  receives  three  coats  of 
Turner's  yellow  in  copal  varnish. 

Polished  Leather  of  the  Original  Color  of  Leather. — 

A  coat  of  a  mixture  of  yellow-ochre,  white  lead,  and 
oil  varnish  is  applied,  and  polished  when  dry.  The 
second  coat  consists  of  Turner's  yellow  mixed  with  copal 
varnish. 

nossiter's  process. 

Mr.  Charles  Nossiter's  patented  process  consists  in 
removing  the  grain  surface  by  splitting  or  buffing,  and 
then  making  a  finish  on  the  surface  thus  obtained,  by 
means  of  a  glass  or  other  roller,  after  which  the  enamel- 
ling is  proceeded  with  in  the  usual  manner.  This  pro- 
cess is  particularly  applicable  to  sheep  and  lamb  skins, 
and  produces  softer,  more  flexible,  and  better-colored 
leather  than  that  made  by  enamelling  the  grain  surface 
of  such  descriptions  of  skins. 


30 


CHAPTER  XLV. 


HALYOESON'S  PROCESS  FOR  RENDERING  HIDES  HARD 
AND  TRANSPARENT. 

Halyor  Halvorson's  process  for  hardening  hides  {Pa- 
tent Office  Report^  1847,  p.  33),  consists  in  subjecting 
them,  in  consecutive  operations,  to  the  action  of  alkaline 
and  astringent  solutions,  and  ultimately  to  that  of  boiling 
oil.  A  horn-like  material,  applicable  to  useful  purposes 
in  the  arts,  is  the  product.  The  patentee  describes  his 
method  as  follows  : — 

"  I  commence  my  process  by  taking  the  raw  hide,  and 
submitting  it  to  what  the  tanners  usually  term  ^sweat- 
ing,' or  putrefaction,  sufficient  to  remove  the  hair,  or  in- 
stead thereof,  I  immerse  the  hide  in  a  solution  of  lime 
or  alkali  proper  to  remove  the  hair.  I  next  place  it  in 
and  submit  it  to  the  action  of  a  boiling  or  hot  bath  of  any 
powerful  astringent  and  alkaline,  or  other  suitable  sub- 
stance sufficient  to  remove  the  animal  oil  or  fatty  matter, 
and  to  full  or  mill  it  up  or  make  it  thicker. 

"  So  far  as  my  experience  goes,  I  find  sulphuric  acid, 
salts  of  tartar,  and  alum,  dissolved  in  water,  to  answer 
a  good  purpose.  I  keep  the  hide  in  the  solution  (in  a 
state  of  ebullition),  and  frequently  agitate  or  stir  the 
liquid,  and  bend  and  unbend,  or  compress  and  open,  or 
handle  or  w^ork  the  hide  by  tongs,  while  it  is  under  the 
influence  of  the  bath,  or  I  remove  it  from  the  hot  bath, 


PROCESS  FOR  RENDERING  HIDES  TRANSPARENT.  459 

and,  having  smeared  my  hands  with  oil  or  grease,  in 
order  to  protect  them  from  injury  from  the  caustic  or 
other  properties  of  the  solution,  I  lay  hold  of  the  hide 
and  squeeze  and  work  it  in  various  ways  in  order  to 
cause  the  liquid  to  penetrate  it,  and  properly  act  upon 
it,  so  as  to  full  or  thicken  it,  and  remove  the  animal  fat 
or  oleaginous  matter;  or,  instead  of  the  above  mode  of 
proceeding,  I  make  use  of  any  suitable  mechanical  means, 
by  which  the  operation  of  the  alkaline  and  astringent 
liquid  may  be  facilitated,  whether  to  remove  the  animal 
oil,  or  to  full  or  thicken  the  hide. 

"After  thus  having  fulled  it  to  the  desired  thickness, 
or  completed  the  process  of  removing  the  extraneous 
animal  oil,  I  rinse  it  in  warm  and  clear  water,  and  dry 
it.  At  this  stage  of  the  process,  the  hide  retains  its 
opacity,  and  will  be  found  to  be  very  easily  affected  by 
atmospheric  changes.  In  damp  weather  it  will  absorb 
moisture,  and  become  more  or  less  soft.  In  cold  or  dry 
weather  it  will  resume  its  hardness.  Consequently,  while 
in  this  state  it  is  unfit  for  many  purposes.  In  order  to 
render  it  semi-transparent,  and  capable  of  resisting  the 
influence  of  ordinary  atmospheric  changes,  or  that  of  a 
considerable  degree  of  heat,  I  next  immerse  it  in  a 
cauldron  of  boiling  or  hot  linseed  or  drying  oil,  or  any 
other  suitable  vegetable  or  other  oil,  possessing  drying 
qualities,  and  keep  it  therein  (while  the  oil  is  boiling), 
until  a  white  or  yellowish  scale  or  crisp  begins  to  form 
on  its  surface.  As  soon  as  this  is  discoverable,  the  hide 
should  be  removed  from  the  oil.  While  hot  it  will  be 
found  soft  and  pliable,  and  capable  of  being  made, 
pressed,  or  moulded  into  various  shapes.  When  cold,  it 
will  be  found  to  have  been  changed  or  converted  into  a 
substance,  resembling,  in  many  respects,  horn  or  tortoise- 


460      PROCESS  FOR  RENDERING  HIDES  TRANSPARENT. 


shell,  and  may  be  bored,  turned,  or  filed,  or  otherwise 
wrought  like  them  or  ivory. 

I  would  here  remark  that,  should  the  hide  thus  pre- 
pared be  designed  for  embossed  work,  such  as  figured 
buttons,  combs,  or  other  articles  of  such  nature,  it  is 
advisable  to  remove  it  from  the  boiling  oil,  as  soon  as  it 
acquires  the  desired  transparency,  and  softness,  and  before 
the  white  scale,  herein  before  alluded  to,  makes  its  ap- 
pearance. 

After  being  thus  prepared,  it  may  be  submitted  to 
pressure  in  the  mould.  During  the  last  portion  of  the 
process,  viz.,  the  boiling  in  oil,  the  material  may  be 
stained  by  incorporating  with  the  oil  any  drying  material 
or  materials,  that  will  be  proper  to  produce  any  desired 
color.  It  may  be  colored  also  in  a  manner  to  resemble 
tortoise-shell,  by  such  modes  as  are  usually  adopted  to 
give  to  horn  such  an  appearance. 

"The  oil  in  ebullition  communicates  a  greater  heat  to 
the  material,  than  the  astringent  alkaline  liquid  does,  in 
consequence  of  which  it  becomes  indurated  when  cold, 
and  susceptible  of  a  high  polish. 

"  The  drying  oil  penetrates  the  pores  of  the  hide  and 
takes  the  place  of  the  animal  oil,  previously  extracted, 
and  by  so  doing,  not  only  renders  the  skin  hard  like 
horn,  but  guards  it  from  the  effects  of  ordinary  atmo- 
spheric changes,  whether  of  temperature  or  moisture. 

"  Where  it  may  not  be  required  to  full  up  or  thicken 
a  hide  to  its  greatest  extent  of  capacity,  the  use  of  an 
astringent  solution  may  be  dispensed  with,  it  being  only 
necessary,  in  such  cases,  to  employ  the  alkaline  solution, 
or  some  equivalent  capable  of  removing  the  animal  oil 
and  extraneous  matters,  and  afterwards  expose  the  skin 
or  hide  to  the  action  of  hot  or  boiling  oil,  all  in  the 
manner  above  set  forth." 


CHAPTER  XLYI. 

CURRYINa  OF  LEATHER. 

The  derivation  of  the  word  Currier"  is  from  the  Latin 
Coriarius,  which  means  a  workman  in  leather;  the  term 
for  skin  being  corium;  and  both  the  ancients  and  the 
moderns  have  understood  currying  as  the  preparation  of 
tanned  skins  for  the  purpose  of  imparting  to  them  the 
necessary  smoothness,  color,  lustre,  and  suppleness. 

Curried  leather  receives  different  designations,  accord- 
ing to  the  modes  of  dressing  it  which  are  employed,  as 
tallowed  leather,  loaxed  and  oiled  leather,  &c.;  and  it  is 
subjected,  in  order  to  receive  the  required  qualities,  to 
the  operation  of  soaldng  or  dipping,  of  treading  or  heating, 
of  stretching,  of  oiling,  of  tallowing,  of  dyeing,  and  of  po- 
lishing. Before  any  of  these  processes  are  commenced, 
the  tails,  foreheads,  teats,  and  parts  of  the  extremities 
are  cut  off,  and  these  remnants  serve  for  upper  soles, 
heels,  &c.  &c. 

Dipping. — The  first  operation  of  the  currier  is  that  of 
dipping  the  leather,  or  softening  it.  For  this  purpose, 
the  skins  are  deposited  in  a  tub,  or  trough,  along  with 
water,  in  which  they  are  allowed  to  remain  until  they 
become  sufficiently  moist ;  or  else  they  are  sprinkled  with 
water  from  a  brush  or  broom,  which  is  a  much  less  ef- 
fectual method.  They  are  then  softened  by  being  trod 
or  beaten  out  upon  a  strong  hurdle  (Fig.  143),  about  a 


462 


CURRYING  OF  LEATHER. 


yard  square,  which  is  either  composed  of  basket-twigs,  or 
of  wooden  pegs  fixed  rectangularly  in  holes  at  intervals 
of  about  five  inches.    The  leather  may  either  be  beaten 

Fig.  143. 


out  with  the  feet,  or  with  an  instrument  called  the  mace. 
If  the  former  are  employed,  the  workman  should  wear 
large  shoes  (Fig.  144)  made  for  the  purpose,  with  three 
thicknesses  of  sole.  Provided  with  these,  he 
Fig.  144.      beats  and  treads  out  the  leather  in  every  di- 
^^^^3     rection,  by  repeated  shuffling  and  stamping 
movements  of  his  heels,  retaining  it  in  place 
by  the  left  heel,  while  the  right  is  made  to  follow  the 
movements  of  the  other  in  every  direction.    This  is  done 
for  a  quarter  of  an  hour  or  longer,  until  the  leather  is 
completely  softened  and  impregnated  with  moisture. 
The  mace  (Fig.  145),  which  is  sometimes  used,  instead 
of  the  feet,  is  made  of  wood,  having  a  handle 
Fig.  145.      eleven  and  a  half  feet  long  (Ure  says  thirty 
^    inches),  with  a  head  or  mallet  four  and  se- 
ven-tenth inches  long,  and  five  and  a  half 
inches  square;  upon  the  two  faces  of  which, 
parallel  to  the  line  of  the  handle,  are  four 
egg-shaped  pegs  of  wood  one  and  a  half  inches 
in  length,  which  are  finely  polished,  so  as  not 
to  tear  the  moistened  leather  when  it  is  beaten 
by  them.    All  skins  intended  to  be  tallowed, 
should  not  only  be  beaten  by  the  feet,  but  with  the  mace; 
but,  while  the  use  of  the  latter  is  very  important,  care 


CURRYING  OF  LEATHER. 


463 


should  be  taken  that  it  be  not  employed  with  such  force 
as  to  be  injurious  to  the  leather. 

The  leather,  after  having  been  properly  softened  b}^ 
these  means,  is  subjected,  upon  the  liorsey  to  the  action 
of  the  cleaners.    The  horse  (Fig.  146)  consists  of  a 


Fig.  146. 


strong,  firm,  flat  plank,  supported  upon  a  frame  by  two 
uprights  and  a  crosspiece,  so  that  it  can  be  made  to  slope 
at  a  greater  or  less  angle.  If  not  sufficiently  heavy  to 
be  immovable,  it  may  be  loaded  with  stones,  or  weights, 
placed  upon  the  frame. 

A  more  convenient  beam  is  that  patented  in  this  coun- 
ty, by  N.  Sargent,  and  shown  by  Fig.  147.    The  up- 

Fig.  147. 


right  is  fitted  with  adjusting  screws,  by  which  it  may  be 
elevated  or  lowered  to  any  desired  height,  as  may  suit 
the  comfort  and  convenience  of  the  workman. 

Formerly,  and  in  some  places  at  the  present  day,  three 


464 


CURRYING  OF  LEATHER. 


instruments  have  been  and  are  used  for  the  cleaning  and 
paring  of  leather;  the  sharp-edged  cleaner^  the  blunt 
cleaner,  and  the  head-knife;  but  the  latter  alone  is  used 
now  in  Paris  for  this  first  working. 

This  knife  (Fig.  148),  which  is  called  in  French  cou- 
teau  a  revers,  on  account  of  the  form  of  its 
Fig.  148.     edge,  which  is  very  much  turned  over,  is  from 


CIEilll^^ 


twelve  to  fourteen  inches  long,  and  from  four 
and  a  half  to  five  and  a  half  inches  broad; 
and  has  two  handles,  one  in  the  direction  of  the  blade, 
and  the  other  perpendicular  to  it,  for  the  purpose  of 
guiding  the  edge  more  correctly  over  the  surface  of  the 
skin. 

The  round-knife  (lunette)^  is  a  circular  knife  from  ten 
to  twelve  inches  in  diameter,  with  a  round,  four  or  five 
inch  hole  in  the  centre,  for  introducing  the  hands.  It  is 
concave,  of  the  form  of  a  spherical  zone;  the  concave 
part  being  that  which  is  applied  to  the  skin,  and  having 
an  edge  a  little  turned  over  on  the  side  opposite  to  the 
skin,  so  as  to  prevent  it  from  entering  too  far  into  the 
leather.  Besides  these,  the  sharp-edged  and  blunt-edged 
cleaners^  Fig.  149,  are  sometimes  used.  The  latter  is 
usually  made  of  an  old  knife,  and  is  pro- 

HMiiiiiiiiMiK.  vided  with  two  handles ;  the  former  may 
be  made  of  an  old  sabre. 

Curriers  are  recommended  to  dispense  with  these 
cleaners,  to  use  the  head  and  round  knife  for  shaving 
and  paring  the  skins  upon  the  horse,  and  to  confine 
themselves  to  the.  employment  of  the  stretching-iron  for 
smoothing  and  scraping  the  leather,  for  filling  up  its 
weak  parts,  removing  the  creases,  and  the  filamentous 
particles  which  project  from  its  surface. 

Shaving, — The  second  operation  of  the  currier  after 
dipping  and  softening  the  skins,  is  to  pare  or  shave  them 


CURRYING  OF  LEATHER. 


465 


with  the  head-knife,  for  the  purpose  of  securing  uniform- 
ity of  thickness  and  regularity  of  surfaces.  When, 
however,  the  leather  presents  many  weak  and  thin 
parts,  this  operation  may  sometimes  be  dispensed  with  or 
postponed,  until  these  have  been  filled  up  by  the  action 
of  the  stretching-iron.  While  preferences  are  given  in 
difierent  places  to  other  modes  of  working  some  kinds 
of  leather,  all  kinds  indifferently  are  shaved,  by  Parisian 
curriers,  with  the  head-knife  and  round-knife :  they  use 
the  French  horse,  however,  for  paring  off  the  borders  of 
the  skins,  with  the  latter  instrument,  and  the  English 
horse,  for  the  other  parts  of  the  operation,  which  are 
conducted  with  the  head-knife. 

For  rendering  the  surface  of  leather  smooth  and 
compact  with  the  stretching-knife,  the  table  has  been 
generally  substituted  for  the  horse. 


Fig.  150. 


Pommelling. — All  leather  should  be  submitted  to  the 
action  of  the  pommel,  so  called,  because  it  clothes  the  hand 
and  performs  its  functions.  This  instrument  is  of  rec- 
tangular shape  and  of  different  sizes,  but  is  usually  about 
thirteen  inches  long,  and  five  inches  broad,  and  is  made 
of  dogwood.  The  upper  surface  is  flat,  and  is  provided 
with  a  wide  leather  strap  nailed  to  the  sides,  which  is 
intended  for  confining  the  hand  of  the  workman.  The 
lower  surface  is  rounded  and  furrowed  over  with  trans- 
verse straight  ridges  and  grooves.    These  grooves  are 


466 


CURRYING  OF  LEATHER. 


sharp-edged  isosceles  triangles  in  section,  and  vary  in 
fineness  according  to  the  size  of  the  pommel^  the  largest 
being  from  seven  hundredths  to  two-tenths  of  an  inch 
deep,  and  two  or  three-tenths  of  an  inch  wide.  (Figs. 
151  and  152.) 


Figs.  151.  152.  158. 


A  large  kind  of  pommel,  called  in  French  the  mar- 
guerite  (Fig.  153),  is  now  employed  for  nearly  all  the 
operations  in  which  the  ordinary  one  was  formerly  used. 
It  is  from  fifteen  to  nineteen  inches  long,  five  inches 
broad,  and  of  a  thickness  in  the  middle  of  from  three  and 
a  half  to  four  and  a  half  inches,  and  at  the  end,  of  from 
one  and  nine-tenths  to  two  and  two-tenths  inches.  As 
it  is  much  more  heavy  and  difficult  to  manage  than  the 
pommel,  a  peg  or  handle  is  placed  at  one  end  for  the 
workman  to  grasp,  while  his  arm  is  passed  under  a  large 
strap,  and  his  elbow  rests  upon  a  cushion  at  the  other 
end.  The  grooves  are  larger  and  further  apart  than 
those  of  pommels,  and  differ  in  size  with  that  of  the 
marguerite,  which  may  be  made  for  particular  purposes, 
larger  or  smaller  than  the  one  which  has  been  described. 

These  instruments  are  the  ones  which  are  the  best 
adapted  for  the  purpose  of  giving  flexibility  and  a  granular 
appearance  to  the  leather.  The  skin  is  first  folded  with 
its  grain  side  in  contact,  then  stretched  out  upon  a  table, 
and  rubbed  strongly  with  the  pommel,  or  7narguerite, 
each  quarter  successively  being  made  to  slide  under  the 
instrument,  over  the  leather  below  it,  first  towards  the 
centre,  and  then  back  to  its  original  position.  This 
mode  of  working  leather,  makes  it  extremely  flexible. 
To  give  the  proper  grain,  the  skin  is  then  stretched  out 


CURKYING  OF  LEATHER.  467 

upon  the  flesh  side,  and  pommelled  from  head  to  tail  and 
crosswise. 

Stretcliing,  —  This  operation  is  performed  with  the 
stretching-iron  (Figs.  154  and  155),  which  is  a  flat  piece 


Fig.  154.  Fig.  155. 


of  iron  or  copper,  a  fourth  of  an  inch  thick  at  top,  and 
thinning  ofi*  at  the  bottom  into  a  blunt  edge,  shaped  like 
an  arc  of  a  very  large  circle.  It  is  about  six  inches  long 
and  four  inches  high,  and  is  provided  with  a  handle  ten 
inches  in  length  and  five  in  height.  An  iron  or  steel 
instrument  is  generally  employed,  as  being  less  likely  to 
wear  out  than  a  copper  one ;  but  the  latter  is  preferred 
by  many,  since  the  leather  is  sometimes  blackened  and 
spotted  by  the  iron.  One  made  of  steel  is  less  objection- 
able on  this  account.  Stretchers  of  other  forms  and 
dimensions  than  the  one  described  above  are  sometimes 
used,  but  they  vary  very  little  from  each  other  in  con- 
struction. Those  formerly  used  were  without  handles, 
and  had  a  copper  rim  to  protect  the  hands  of  the  work- 
man. 


Fig.  156. 


The  skin  being  placed  upon  the  table,  the  workman 
grasps  the  stretching  iron  in  both  hands  (central  figure, 


468 


CURRYING  OF  LEATHER. 


Fig.  156),  and  holding  it  nearly  perpendicular  upon  the 
leather,  forcibly  scrapes  the  thick  places  so  as  to  render 
them  of  uniform  thickness  with  the  rest,  to  remove  par- 
ticles of  flesh  or  projecting  filaments,  and  to  fill  up  the 
thin  and  weak  spots.  The  leather  is  rendered  smoother, 
softer,  more  compact,  and  equal  throughout  by  this  opera- 
tion, to  which  all  kinds  of  skins  should  be  subjected; 
and  when  thus  treated,  there  is  no  absolute  need  of  the 
application  to  them  of  oil  or  tallow. 

Woi'hiyig  with  the  Round-Knife, — Leather  is  subjected 
to  the  action  of  the  round-lmife  (Fig.  157),  an 
instrument  which  has  already  been  described, 
after  its  edges  have  been  sloped  off  with  the 
head-knife,  an  operation  which  is  performed 
upon  the  horse  by  shaving  off  a  layer  of  two  inches  in 
breadth  all  around  the  borders  of  the  skin.  They  are 
then  worked  with  the  round-knife  upon  the  dresser,  which 
is  a  cylindrical  wooden  bar  fastened  at  a  height  of  five 
feet,  three  inches  from  the  ground,  by  its  two  ends,  to 
two  buttresses  projecting  from  the  wall. 

A  thick  cord  is  stretched  along  the  upper  surface  of 
this  bar.  The  end  being  separated  from  the  dresser,  the 
breadth  of  the  skin  is  folded  over  it,  the  grain  being 
within,  and  the  skin  is  turned  over  and  stretched  around 
the  beam,  its  end  being  firmly  held  between  the  bar  and 
the  cord,  which  is  still  more  tightly  pressed  down  by  the 
leather  which  envelops  it.  (Fig.  158,  a  skin  stretched 
upon  the  dresser.) 


Fig.  158. 


Fig.  159. 


CUKETING  OF  LEATHER. 


469 


The  skin  being  thus  stretched,  the  workman  seizes 
the  lower  part  of  it,  and  confines  it  in  place  by  a  pair 
of  pincers  (Fig.  159),  attached  to  his  girdle,  and  grasp- 
ing the  round-knife  in  both  hands,  works  the  leather 
with  it  from  above  downwards,  removing  the  fleshy, 
thick,  or  projecting  parts.    This  paring  (Fig.  160),  which 

Fig.  160. 


Fig.  161. 


is  an  operation  requiring  the  utmost  care,  is  generally 
done  from  tail  to  head,  and  sometimes  across  the  grain. 

The  round-knife  must  be  occasionally  sharpened  upon 
an  oiled  stone  (Fig.  161)  to  keep  it  in 
good  condition,  and  the  edge  must  be  kept 
turned  over  by  a  steel,  so  as  to  prevent  it 
from  entering  too  far  into  the  leather. 

According  to  Dessables,  this  operation  is  at  the  present 
day  used  only  or  chiefly  for  goat-skins,  all  the  other 
kinds  being  pared  with  the  head-knife.  A  workman  can 
pare  an  ordinary  skin  in  an  hour  upon  the  dresser,  and 
six  or  eight  dozen  goat-skins  in  a  day. 

Before  being  subjected  to  the  operations  of  the  cur- 
rier, hides  are  frequently  cut  in  half,  and  are  still  more 
often  made  into  an  almost  square  form  by  cutting  off  the 
head  and  belly  parts,  leaving  the  tail  still  attached  to 
them.  These  square  hides  contain  all  the  best  and 
strongest  parts  of  the  leather;  the  head  and  belly  por- 


470 


CURRYING  OF  LEATHER. 


tions  being  the  weakest,  and  being  only  used  by  shoe- 
makers for  the  finest  or  upper  soles. 

STRETCHED  LEATHER. 

The  skins  of  cows  and  of  young  oxen  made  into  crop- 
leather  are  the  only  ones  which  are  fit  for  stretchers^  and 
when  thus  prepared  do  not  require  the  application  of  oil 
or  tallow.  All  curriers  do  not  pursue  the  same  method, 
some  preparing  crop-leather,  or  that  which  has  been 
tanned  in  bags  by  the  Danish  plan. 

After  the  leather  has  been  dried,  it  is  moistened, 
fleshed  on  the  horse,  moistened  a  second  time,  scraped 
with  the  stretcher,  and,  when  thoroughly  dry,  is  well- 
slicked  with  the  glass-polisher,  so  as  to  smooth  the  grain. 

Before  stretching  a  cow-skin,  the  head  was  formerly 
removed,  as  being  too  thick  to  be  properly  smoothed ;  but 
it  is  at  the  present  day  usually  left  on,  as  it  forms  a  con- 
siderable addition  to  the  weight  of  the  leather.  The 
skins  are  first  cut  in  half  from  head  to  tail,  the  whole 
skin  being  too  large  to  be  properly  worked,  and  are  then 
deposited  in  tubs  full  of  water,  in  which  they  are  allowed 
to  remain  for  twelve  hours.  When  thoroughly  wet,  they 
are  taken  out,  are  spread  on  the  table  and  worked  from 
tail  to  head  with  the  stretching-iron,  or,  if  it  is  preferred, 
they  can  be  lightly  pared  on  the  horse.  Either  of  these 
operations  being  completed,  the  skins  are  well  pum- 
melled and  worked  with  the  marguerite  from  tail  to  head 
and  cross-wise,  and  then  dried.  When  they  have  been 
stretched,  and  deprived  of  the  greater  part  of  their  moist- 
ure, they  are  dampened  slightly  with  a  wet  cloth  upon 
the  hair  side,  and  are  again  scraped  with  the  stretching- 
iron.  The  hair  side  is  again  well  moistened  with  the 
wet  cloth;  the  skins  are  then  dried,  placed  under  the 


CURRYING  OF  LEATHER. 


471 


press,  and,  after  three  or  four  hours'  exposure  to  it,  hung 
up  to  dry.  When  nearly  dry,  they  are  piled  up  in  a  dry 
and  clean  place,  and  covered  with  weighted  planks,  when 
the  operation  is  completed. 

Leather,  prepared  in  this  way,  is  not  blackened,  and 
does  not  require,  as  has  been  before  stated,  the  applica- 
tion of  oil  or  grease.  It  is  used  by  saddlers  and  harness- 
makers,  and  by  shoemakers  for  the  soles  of  pumps,  and 
the  upper  soles  of  large  shoes. 

SLEEKED  LEATHER. 

Sleeked  leather,  which  is  intended  chiefly  for  saddlers 
and  harness-makers'  use,  should  be  made  of  strong  hides; 
thick  cow-skins  and  ox-hides  being  generally  preferred 
for  the  purpose. 

The  hides,  as  they  come  from  the  tan-yards,  are  cut  in 
two,  are  deprived  of  the  head  parts,  soaked  in  the  tub 
and  trod  out,  care  being  taken  not  to  allow  them  to  be- 
come too  thoroughly  saturated  with  water.  They  are 
then  lightly  fleshed  with  the  head-knife,  pommelled,  and 
half  dried  by  exposure  to  the  air.  In  this  state,  they 
are  again  trodden  out,  hung  up  to  dry,  and  trodden  out 
for  the  third  time;  pommelled  on  both  sides,  and  at  last 
hung  up  until  thoroughly  dried.  In  order  to  make 
known  tiie  weight  of  each  skin,  they  are  marked  with 
Koman  characters  designating  it. 

Before  being  tallowed,  the  flesh  sides  are  rapidly  flamed 
by  being  drawn  over  a  blaze  of  fire  from  lighted  straw, 
so  as  to  make  them  more  penetrable  by  the  grease.  The 
kind  of  fatty  matter  is  left  to  the  choice  of  the  operator, 
but  mutton-suet  is  undoubtedly  the  best,  and  gives  a 
finer  lustre  to  the  leather  than  any  other,  but  is  more 
expensive.    The  Parisian  curriers  chiefly  make  use  of 


472 


CUERYING  OF  LEATHER. 


suet  rendered  from  kitchen  drippings.  Six  and  a  half 
pounds  of  suet  are  required  for  a  hide  of  ordinary  size. 

When  the  grease  is  melted  and  heated  to  the  proper 
point,  which  the  workman  himself  must  decide  upon,  the 
skin  is  stretched  upon  the  table,  and  the  operation  com- 
menced by  spreading  the  tallow  over  the  surface  with  a 
tallowing  cloth  or  mop  (Fig.  162),  which  is  made  of  the 
Fig  u'>    f^^^^^^J      fleecy  parts  of  blanket-stuff.    It  is 
from  fifteen  to  nineteen  inches  long;  a  handle 
^■i     being  made  for  it  by  binding,  or  tying  up  from 
eleven  to  thirteen  inches  of  its  length,  leaving  a 
tuft  long  enough  to  answer  the  purposes  of  a  mop. 

The  grease  is  first  applied  upon  the  flesh  side,  as  being 
the  most  absorbing  surface,  and  then  upon  the  grain ; 
and  more  of  it  is  rubbed  over  the  groins,  edges,  and  thin 
parts,  than  over  the  rest,  so  as  to  increase  their  strength 
and  body.  A  good  workman  can  tallow  a  hide  in  about 
five  minutes. 

When  greased,  the  skins  are  folded  square,  the  hair  side 
in,  and  are  then  soaked  in  a  tub  during  eight  or  ten  hours ; 
after  which  they  are  trod  out  in  water  and  beaten  with 
the  mace  until  deprived  of  most  of  their  watery  contents. 
They  are  then  again  moistened  with  a  wet  broom  (Fig. 
163),  or  soaked  for  a  time,  and  once  more  beaten  in 

Fig.  163. 


every  direction.  The  leather  is  then  pommelled  with 
the  margiterite  upon  the  flesh;  and  the  hair  side  is  pom- 
melled from  tail  to  head,  and  crosswise,  until  the  grain 


CURRYING  OF  LEATHER. 


473 


is  well  smoothed,  when  the  skin  is  placed  upon  the  table 
with  the  hair  side  up,  and  the  surface  is  smoothed  by  the 
forcible  use  of  the  stretching-iron. 

The  leather  is  now  blackened  wdiile  still  upon  the 
table,  being  moistened  before  this "  operation,  if  it  has 
become  too  dry,  since  a  certain  degree  of  humidity  is 
necessary  to  enable  it  to  receive  the  color.  For  this 
purpose,  a  mop  of  wool,  or  brush  of  horse-hair,  is  dipped 
in  the  composition  prepared  for  the  purpose,  and  the 
hair  side  is  thoroughly  rubbed  with  it  in  every  direction 


After  the  first  black,  the  leather  is  three-quarters  dried 
by  exposure  to  the  air,  and  the  stretching-iron  is  again 
passed  over  the  surface,  great  care  being  taken  to  avoid 
scratching  it;  uniformity  and  smoothness  of  surface 
being  secured  by  moving  the  instrument  constantly  and 
regularly  in  one  direction,  away  from  the  position  of  the 
workman.  The  leather  is  made  to  appear  thicker  and 
uniform  by  paring  off  the  edges  with  a  hooked  knife 


leather,  and  when  any  parts  of 

the  surface  remain  of  a  red  color,  even  a  third  may  be 
requisite.    The  second  coat  is  applied  in  the  same  man- 


(Fig.  164). 


Fig.  164. 


(Fig.  165). 

Two  applications  of  black  are 
generally   required   for  sleeked 


Fig.  165. 


31 


474 


CURRYING  OF  LEATHER. 


ner  as  the  first;  the  leather  is  again  partially  dried,  and 
the  surface  slicked,  until  the  marks  of  the  stretching- 
iron  have  been  entirely  removed. 

When'  the  leather  is  of  a  fine  black  color  and  perfectly 
dry,  it  is  exposed  to  the  action  of  a  press  for  a  time  not 
longer  than  two  weeks,  during  which  it  is  increased  in 
density  and  firmness,  the  excess  of  tallow  being  forced 
out  from  it.  If  perfectly  dry  when  placed  in  the  press, 
it  retains  the  original  appearance  of  its  surface,  but  if 
still  somewhat  moist,  it  is  usually  found  covered  with 
mould  when  taken  out. 

In  order  to  give  the  last  dressing  to  these  skins,  the 
hair  side  is  well  wiped,  so  as  to  remove  any  portions  of 
grease  remaining  upon  it,  or  the  mould  which  has  formed 
on  the  surface.    A  polish  is  given  with  sour 
'    beer  or  barberry  juice,  and  the  surface  is  slicked 
with  a  very  smooth  stretching-iron  or  a  lump 
of  smooth  glass  (Fig.  166). 

If  any  spots  of  grease  or  defects  of  surface 
remain,  the  parts  which  are  thus  deficient  are  gently 
rubbed  with  a  cloth  dipped  in  the  polishing  liquid,  until 
they  become  perfectly  bright.  The  leather  is  finally 
hung  up  to  dry  in  a  place  not  exposed  to  the  direct  rays 
of  the  sun. 

For  blacking  leather,  the  Parisia^j  carriers  usually  em- 
ploy hatters'  black,  which  is  composed  of  logwood,  nut- 
galls,  gum,  and  copperas. 

The  best  dye  is  made  in  the  following  manner :  Scraps 
of  old  rusted  iron  are  deposited  in  a  deep  vessel  and 
covered  with  sour  beer,  which  is  allowed  to  act  upon 
them  for  three  months.  A  red  liquid  is  thus  formed, 
which  is  a  solution  of  acetate  of  iron,  and  which  blackens 
the  leather  better,  and  with  more  rapidity,  than  the  solu- 
tion of  copperas. 


CURRYING  OF  LEATHER. 


475 


Another  liquid  may  be  made  use  of,  which  is  less  ex- 
pensive and  requires  less  time  in  the  preparation.  Sour 
beer  is  mixed  with  yeast  from  barley,  and,  after  twenty- 
four  hours,  is  added  to  a  solution  made  by  boiling  cop- 
peras in  vinegar,  care  being  taken  first  to  remove  all  the 
yeast  from  the  surface.  A  mixture  of  solutions  of  sul- 
phate and  of  acetate  of  iron  is  thus  formed. 

TALLOWED  SKINS,  OR  GRAINED  LEATHER. 

Tallowed  or  grained  cow-skins  are  those  the  grain  of 
which  has  been  brought  out,  instead  of  being  smoothed 
down  and  polished,  as  in  sleeked  leather.  These  skins 
are  softer  and  more  flexible  than  the  latter,  and  are  less 
liable  to  be  penetrated  by  moisture ;  trunk-makers,  sad- 
dlers, and  harness-makers  make  use  of  them  for  applica- 
tions of  leather  which  require  these  qualities,  and  the 
largest  of  them  for  carriage-tops. 

For  the  preparation  of  this  kind  of  leather,  the  finest 
cow-skins  are  selected,  and  these  are  not  cut  in  half,  but 
are  dressed  entire.  The  skins  are  first  trodden  out  with 
the  feet  until  the  irregularities  of  surface  are  made  to 
disappear,  and  are  then  pared  with  the  head-knife,  in 
order  to  secure  perfect  uniformity  of  surface.  The  edge 
of  this  knife  should  be  perfectly  straight  and  even,  so 
that  the  leather  may  not  be  streaked  or  scratched  by  its 
use.  After  this  operation,  the  skin  is  half  dried,  and 
then  worked  again  with  the  feet  while  in  that  state,  and 
trodden  out  so  as  to  be  even  and  free  from  all  depressions 
of  surface. 

The  leather  is  now  again  exposed  to  dry,  but  not  to 
complete  dessication;  it  is  beaten  once  more,  and  then 
rolled  up  first  upon  the  flesh,  and  afterwards  upon  the 
hair  side,  by  which  the  creases  are  made  to  disappear. 


476 


CURRYING  OF  LEATHER. 


If  it  has  become  too  hard  for  this  operation,  it  is  moist- 
ened by  sprinkling  with  water  from  a  brush.  Finally,  it 
is  pommelled  with  the  cork  from  tail  to  head. 

The  leather  is  now  dried,  not  thoroughly,  but  suffi- 
ciently to  allow  merely  an  insensible  amount  of  moisture 
to  remain  in  it,  and  is  then  tallowed  in  the  manner 
already  described,  after  having  been  flamed  on  both  sides. 
Before  this  process,  some  tanners  are  in  the  habit  of 
sprinkling  water  from  a  brush  over  both  surfaces,  so  as 
to  increase  the  pliability  of  the  leather;  but  the  practice 
is  improper,  inasmuch  as  the  excess  of  water  must  pre- 
vent the  grease  from  thoroughly  penetrating  the  sub- 
stance. From  3i  to  4i  lbs.  of  tallow  are  usually  re- 
quired for  a  cow-skin,  and  rather  more  than  1  lb.  for  a 
thick  calf-skin. 

After  the  skins  have  been  tallowed,  they  are  rolled, 
and  left  folded,  up  with  the  hair  side  within,  for  some 
hours  or  even  days.  They  are  then  folded  square,  and 
placed  to  soak  in  a  tubfull  of  water  during  eight  or  ten 
hours,  and  are  worked  while  in  the  water,  until  the  ex- 
cess of  grease  which  has  remained  upon  their  surfaces, 
is  washed  or  floated  off.  The  soaking  has  been  sufficient 
when  these  latter  assume  a  uniformly  white  appearance. 

In  order  to  bring  out  the  grain,  the  leather  is  now  well 
worked  with  the  marguerite^  and  the  hair  side  is  pom- 
melled, after  which  both  sides  are  cleaned  with  a  horse- 
hair brush,  and  the  creases  are  taken  out  from  the  parts 
which  have  been  folded,  by  the  use  of  a  smooth  stretch- 
ing-iron (Fig.  167),  the  operation  being  conducted  upon  a 
Fig.  167.  clean  table.  The  skins  are  then  sprinkled  with 
<^  ^  water,  cleaned  again,  doubled  up  and  hung 
out  to  dry,  retouched  with  the  stretching- 
iron,  and  finally  moistened  slightly  before  the  application 
of  the  black. 


CURRYING  OF  LEATHER. 


477 


ThQ  blacking  composition  is  prepared  and  applied  in 
the  same  manner  as  in  the  case  of  sleeked  leather.  The 
skins  are  then  half  dried,  blacked  a  second  time,  smoothed 
with  the  stretching-iron,  wiped,  folded  up  with  the  hair 
side  wdthin,  and  piled  upon  each  other  in  that  condi- 
tion. They  are  then  taken  down,  blacked  a  third  time, 
smoothed  and  wiped  as  before,  and  then  perfectly  dried. 
They  then  receive  a  coat  of  sour  beer,  and  the  four 
quarters  are  worked  with  the  margueodte ;  the  hair  side  is 
pommelled  across,  and  rubbed  with  a  piece  of  old  blanket 
or  flannel,  and  a  second  coating  of  sour  beer  is  applied. 

When  smoothed  and  cleaned  by  these  means,  the 
lustre  is  brought  out  by  the  use  of  the  stretching-iron,  by 
wiping  with  the  old  flannel,  and  by  rubbing  the  surface 
lightly  with  a  smooth,  compact  piece  of  woollen  stuff 
dipped  in  the  barberry  juice.  The  surface  is  then  pom- 
melled, first  obliquely,  afterwards  across  the  breadth  of 
the  skin,  and  finally  from  tail  to  head,  so  as  to  round  off 
the  grain  as  much  as  possible. 

Finally,  to  give  the  last  dressing  to  the  leather,  it  is 
heated  again  with  sour  beer,  exposed  anew  to  the  air 
until  dry,  and  once  more  rubbed  with  a  cloth  dipped  in 
barberry-bush  juice. 

A  workman  is  usually  occupied  eleven  or  twelve 
days  in  preparing  thus  completely  a  dozen  black  skins. 

Tallowed  hides  are  made  use  of  by  trunk-makers, 
harness-makers,  and  saddlers,  and  serve  for  saddle-flaps 
and  carriage-covers;  the  largest  and  finest  of  them  being 
reserved  for  carriage-tops.  One  of  these  skins,  without 
natural  defect,  and  perfectly  prepared  in  every  part,  is 
always  looked  upon  by  the  currier  as  the  triumph  of  his 
art. 

Different  materials  may  be  used  for  the  purpose  of 
giving  a  lustre  to  skins  of  this  kind,  as  sumach,  hot 


478 


CURRYING  OF  LEATHER. 


ooze  and  water,  sour  wine,  or  weak  brandy.  By  dissolv- 
ing gum  Arabic  and  sugar  in  sour  beer,  an  admirable 
liquid  for  the  purpose  may  be  obtained.  Many  other 
means  are  employed  for  giving  a  gloss  to  the  surface, 
some  consisting  of  sugar  or  molasses  dissolved  in  beer, 
others  of  infusions  of  cassia  in  beer  and  vinegar,  sepa- 
rately prepared,  and  then  mixed  together;  cherries,  goose- 
berries, or  common  gum  can  be  equally  well  used  for  the 
purpose.  All  of  these  substances  are  less  expensive  than 
the  barberry,  and  quite  as  efl&cacious. 

WATER-LEATHER. 

This  name  applies  to  the  larger  and  finer  neat-skins, 
which  are  sent  direct  from  the  tannery  to  the  currier, 
who  does  nothing  but  pare  and  expose  them  to  the  air 
before  sending  them,  still  in  the  wet  state,  to  the  carriage- 
maker.  The  latter  does  not  receive  these  skins  until 
about  to  make  use  of  them.  He  then  places  them  upon 
the  carriage,  fixes  them  in  position,  and  without  making 
other  changes,  blackens  and  varnishes  them.  The  car- 
riage-tops made  in  this  way  are  called  imperials,  or 
capotes. 

OIL-LEATHER. 

Two  kinds  of  oil-leather  are  manufactured,  the  one 
black,  intended  for  the  harness-maker;  and  the  other 
uncolored,  for  the  use  of  shoemakers.  This  kind  of 
leather  is  exceedingly  durable,  and  curriers  always  select, 
for  the  preparation  of  it,  the  most  entire  and  well-tanned 
skins  they  can  find. 

Whether  skins  are  intended  to  be  hlachened  or  not, 
they  should  in  either  case  be  dipped,  but  after  this  part 


CURRYING  OF  LEATHER. 


479 


of  the  operation  has  been  gone  through  with,  they  should 
be  kept  separate,  as  the  future  processes  are  essentially 
different  for  the  two  kinds. 

Those  skins  intended  to  be  blackened  on  the  hair-side, 
should  alone  be  beaten.  The  operation  is  then  finished 
with  the  round  or  head  knife.  At  first,  they  are  treated 
like  tallowed  hides ;  that  is,  they  are  dipped,  and  then 
beaten,  if  the  intention  be  to  trim  them  with  the  round- 
knife,  and  they  are  fleshed  if  this  is  not  the  case.  They 
are  then  worked  with  water  in  a  cask  (Fig.  168),  with  a 


Fig.  168.  Fig.  169. 


long  pestle  (Fig.  169).  A  number  can  be  operated  upon 
at  a  time;  and  as  the  object  is  to  make  them  pliable  and 
soft,  they  are  often  treated  in  this  way  seven  or  eight 
times,  being  each  time  re-dipped,  and  worked  in  the  same 
manner. 

After  the  skins  have  thus  been  well  worked,  the  flesh 
side  is  stretched  upon  mai'ble  tables,  and  the  hair  side 
worked  with  the  stone,  and  to  extend  them  thoroughly, 
the  stretching-iron  is  well  laid  on,  by  which  process  all 
the  water  is  pressed  out.  The  stone  used  for  the  pur- 
pose is  a  piece  of  good  grit  stone,  set  in  a  handle  in  the 
same  manner  as  the  stretching-iron.  The  skins  having 
in  this  way  been  freed  from  the  greater  portion  of  their 


480 


CURRYING  OF  LEATHER. 


watery  contents,  are  then  exposed,  for  the  purpose  of 
drying,  either  in  the  open  air  or  within  the  building; 
one  hour's  exposure  usually  sufficing  in  summer,  while 
in  winter  many  more  are  required.  After  being  suffi- 
ciently dried,  they  may  at  once  be  held  in  readiness  for 
the  application  of  the  oil. 

Fish-oil  alone  is  sometimes  used  for  this  purpose,  but 
the  experience  of  nearly  a  century  has  proved  that  train- 
oil  scouring  is  of  all  fatty  substances  the  best  for  the 
purpose.  It  is  a  mixture  of  fish-oil  and  of  potash,  which 
has  already  served  to  clean  skins  converted  into  chamois 
leather;  and  many  advantages  are  obtained  by  using  it. 
It  has  more  density  than  ordinary  fish-oil,  and  is  more 
completely  absorbed  by  the  leather.  Its  saponaceous 
quality  contributes  to  give  softness  and  tenacity,  and  less 
of  it  is  required  than  of  oil.  Its  quality  should,  however, 
be  well  ascertained  before  using  it,  as  if  it  has  not  been 
well  boiled,  and  still  contains  water,  it  will  not  possess 
the  proper  penetrating  power.  Train-oil  scouring  can  be 
procured  in  all  places  where  chamois  leather  is  manu- 
factured, but  that  used  by  French  and  Parisian  curriers 
is  almost  entirely  supplied  by  Grenoble,  Strasburg,  and 
Niort. 

According  to  Delalande,  neat's-foot  oil  adds  to  the 
good  qualities  of  leather.  It  is  only  necessary  to  boil 
the  feet,  &c.,  thoroughly  in  water,  to  draw  off  the  liquor, 
and  place  it  in  a  kettle  with  water  heated  to  the  boiling 
point.  This  is  boiled  for  nearly  twenty-four  hours.  The 
pure  oil  which  rises  to  the  top  is  drawn  off,  and  placed 
in  another  kettle  containing  water  at  about  125°  F. 
After  allowing  it  to  remain  at  this  temperature  for 
twenty-four  hours  more,  it  is  cooled,  and  three  different 
layers  of  oil  which  rise  to  the  surface,  are  drawn  off  sepa- 
rately by  as  many  spigots  in  the  side  of  the  vessel.  The 


CURRYING  OF  LEATHER. 


481 


heaviest  of  these  is  said  by  Delalande  to  render  leather 
perfectly  impervious  to  water. 

Whatever  be  the  quality  of  the  scouring,  it  is  impos- 
sible to  employ  it  alone,  but  it  must  invariably  be  mixed 
with  fish  oil.  The  proportions  of  this  mixture  it  is  im- 
possible to  give  accurately,  as  they  depend  upon  differ-  • 
ent  circumstances,  some  of  which  have  reference  to  the 
temperature  of  the  air,  the  kind  of  leather  employed, 
and  the  dressing  intended  to  be  given  to  it,  and  others 
to  the  consistence  of  the  scouring  itself,  and  finally  to 
the  peculiar  mode  of  operating  pursued  by  the  currier. 
Thus  in  summer,  but  a  small  quantity  of  oil  is  added  to 
make  the  mixture,  while  in  winter  a  much  larger  pro- 
portion is  required.  Poor  and  thin  hides,  which  have 
been  left  too  long  a  time  in  the  lime-pits,  require  but 
little  oil  and  a  good  deal  of  oil  scouring,  because  they 
cannot  retain  much  of  the  oleaginous  matter,  and  would 
absorb  too  quickly  that  which  has  the  greatest  pene- 
trating power.  When  the  skins  are  exposed  to  the 
action  of  the  mixture,  they  imbibe  upon  the  first  appli- 
cation much  more  than  upon  the  second.  The  denser 
the  oil  scouring,  the  more  oil  is  required ;  but  the  quan- 
tity of  the  latter,  which  is  often  made  to  amount  to 
one-fourth  of  the  mixture,  should  never  exceed  one-half 
of  it. 

Experience  has  shown  that  for  a  neat-skin  weighing 
16  lbs.,  4  lbs.  of  the  oily  material  are  required,  and  that 
10  lbs.  are  expended  upon  a  dozen  calf-skins  weighing 
30  lbs.,  thus  giving  the  proportions  of  about  one-fourth 
of  their  weight  of  oil  for  the  former,  and  one-third  for 
the  latter. 

The  skins  which  are  intended  to  undergo  the  oiling 
process  should  contain  just  enough  water  to  enable  them 
to  yield  a  small  quantity  upon  being  wrung  out.  If 


482 


CURRYING  OF  LEATHER. 


they  be  dry  or  only  slightly  moistj  they  will  absorb  the 
oil  too  rapidly,  while  it  is  essential  for  the  perfection  of 
the  process  that  their  substance  be  gradually  penetrated 
by  it.  When,  on  the  contrary,  they  are  still  quite  wet, 
they  take  it  up  slowly,  in  proportion  as  they  lose  their 
»  water.  The  operator  should,  therefore,  before  oiling 
them,  carefully  ascertain  that  they  are  just  wet  enough 
for  the  purpose,  and  should  moisten  again  those  parts  of 
them  which  have  become  too  dry.  The  other  extreme 
should,  however,  be  as  carefully  guarded  against;  as, 
when  the  hides  are  very  wet,  too  much  of  the  oil  scouring 
is  consumed  in  forming  a  soapy  compound  with  the 
water. 

After  the  skins  have  received  their  coating  of  oil  upon 
both  sides,  and  the  workman  has  uniformly  distributed 
it  over  the  surfaces  with  the  hand  or  the  t  alio  wing-cloth, 
he  hangs  them  up  by  the  hind  quartei^s,  and  allows  them 
to  remain  in  the  air  long  enough  to  absorb  their  contents 
of  oil,  taking  care  not  to  let  them  be  exposed  to  the  ex- 
treme heat  of  the  sun  or  to  a  great  draught  of  air,  as  if 
they  be  dried  too  rapidly,  the  oil  will  not  penetrate  them 
in  the  gradual  manner  necessary  for  the  perfection  of 
the  process.  Ten  or  twelve  hours  of  exposure  are  usu- 
all}^  sufficient  in  summer,  while  in  winter,  two  or  three 
days  are  often  required. 

The  bellies  of  neat  sides  require  less  oil  than  the  other 
parts,  while,  on  the  contrary,  those  of  calf-skins  absorb 
more. 

The  oil  scouring  should  never  be  warmed  in  winter,  as 
is  often  done. 

No  uniform  method  of  oiling  skins  is  pursued.  In  some 
establishments,  the  oil  alone  is  applied  to  the  hair  side, 
while  a  mixture  of  oil  and  scouring  is  placed  upon  the 
flesh  side ;  and  in  others,  again,  the  mixture  is  applied  to 


CURRYING  OF  LEATHER. 


483 


both  surfaces.  Some  curriers  again,  make  use  of  no  oil 
whatever ;  but  apply  the  oil  scouring  to  both  sides,  tak- 
ing care  only  to  stuff  the  flesh  side  most  plentifully  with 
it.  These  different  modes  of  proceeding  seem  to  succeed 
almost  equally  well,  and  we  refrain  from  condemning 
any  one  of  them ;  but  will  observe  that  in  every  instance 
care  must  be  taken  not  to  give  the  hair  side  too  large  a 
quantity  of  scouring,  or  it  will  be  very  difficult  to  give 
the  requisite  gloss  to  that  surface.  It  is  also  necessary 
to  add,  that  those  skins  intended  for  saddlers'  use,  do 
not  require  one-third  as  much  oil  stuffing  as  is  needed 
for  shoemakers'  leather. 

After  the  skins  have  become  sufficiently  dry,  they  are 
to  be  fulled,  and  recharged  with  some  of  the  fish-oil  and 
a  lesser  quantity  of  oil  scouring,  again  fulled,  and  finally, 
the  hair  side  is  to  be  thoroughly  scoured  by  a  brush 
dipped  in  a  solution  of  potash.  The  skins  are  imme- 
diately after  this  blackened,  care  being  taken  to  keep 
the  borders  clean.  The  blacking,  which  has  already 
been  described,  is  used  and  always  applied  in  the  same 
manner. 

After  the  first  blacking,  the  skins  are  pommelled  cross- 
wise, a  second  coating  of  black  is  applied,  and  they  are 
exposed  to  the  air  until  completely  dry.  When  dry,  they 
are  beaten,  pommelled,  and  trimmed,  passed  over  with 
the  head  or  the  round  knife,  then  rubbed  with  the  cork, 
and  the  process  is  completed  by  lightly  oiling  the  hair 
side.  (See  a  cork  pommel,  at  Fig  170.) 

These  last  operations,  again,  are  differently 
performed  by  different  curriers.    Some,  after  ^^^^A 
the  first  coating  of  black,  do  not  full  the  skins,  ' 
but  pass  the  stretching-iron  over  them  upon  the  table. 
They  then  moisten  the  hair  side,  pass  over  it  the  solu- 
tion of  potassa,  and  give  the  second  coat  of  black.  To 


484 


CURRYING  OF  LEATHER. 


smooth  them  and  to  impart  grain,  they  pommel  them 
from  tail  to  head,  and  also  across  the  grain.  Either  of 
these  methods  may  be  pursued,  but  the  last  is  preferable. 
As  harness-makers  need  for  their  purposes  very  strong 
skins,  square  oiled  hides  or  croupous  are  prepared  espe- 
cially for  them,  or  skins,  the  heads  and  belly  pieces 
{tetes  et  ventres)  of  which  have  been  cut  off,  by  which 
each  skin  is  reduced  to  one  metre  forty-six  in  length, 
and  one  metre  and  some  centimetres  in  breadth.  (See  a 
croupon,  Fig.  171.) 


Uncolored  leather,  which  remains  to  be  noticed,  will 
be  considered  in  a  separate  article. 


Waxed  skins  are  those  which  have  been  rubbed  over 
with  wax,  melted  and  maintained  at  a  heat  sufficiently 
great  to  allow  it  to  penetrate  the  leather.  As  this  mode 
of  treating  them  is  costly,  very  few  of  them  are  now 
prepared,  particularly  as  the  saddlers  and  harness-makers, 
for  whose  use  they  have  generally  been  furnished,  no 
longer  buy  them.  Nowadays  the  name  is  applied  almost 
entirely  to  the  tallow  hides,  which  originally  had  great 
consistency,  as  they  were  prepared  with  great  care. 
Some  manufacturers,  to  give  great  firmness  to  certain 
skins,  add  to  the  tallow  from  one-eighth  to  one-fourth 
of  wax.    In  general,  smooth  sleeked  skins,  with  this 


Fig.  171. 


WAXED  LEATHER. 


CURRYING  OF  LEATHER. 


485 


property  of  great  firmness,  are  used  and  sold  by  carriage- 
makers  as  waxed  skins,  and  are  held  in  great  esteem  for 
their  beauty  and  durability. 

ENGLISH  HIDES. 

Those  smooth  and  well-grained  skins  are  so  called, 
which  are  made  pliable  by  means  of  tallow,  and  retain 
their  reddish  or  yellowish  color.  For  this  purpose  well- 
tanned  skins  of  the  best  quality,  which  are  white  on  the 
hair  side,  perfectly  clean,  and  free  from  greenness  are 
selected.  Those  from  Louviers  and  Nemours  are  pre- 
ferred. These  skins  are  dipped  in  the  same  manner  as 
the  sleeked  leather,  and  the  workman  should  handle 
them  with  the  utmost  care,  as  the  least  spot  renders  them 
unfit  for  use.  They  are  then  worked  and  pared,  after 
having  been  dipped  and  exposed  to  the  air,  and  are  well 
pommelled  on  both  sides  to  efiace  the  wrinkles,  and  dried 
thoroughly  before  being  tallowed. 

When  this  is  done,  the  hair  side  is  wet  with  a  clean 
cloth  dipped  in  pure  water,  to  prevent  the  tallow  from 
entering  the  weak  parts.  The  tallow  applied  to  the  flesh 
side  should  not  be  as  warm  as  that  used  for  the  tallow 
hides  and  sleeked  leather;  and  as  one  of  the  principal 
objects  of  the  process  is  to  make  them  retain  their 
natural  color,  only  a  small  quantity  should  be  applied, 
so  that  it  shall  not  penetrate  fully  to  the  hair  side. 
After  being  tallowed,  the  hides  should  be  soaked  for  a 
half  hour  in  clean  water.  Dessables  thus  describes  the 
process. 

"When  the  skins  have  been  soaked,  they  should  be 
worked  in  water,  stretched,  and  a  light  and  uniform 
coating  of  fish-oil,  or  what  is  better,  linseed-oil,  spread 
over  the  hair  side  with  a  piece  of  wool  or  cloth.  They 


486 


CURRYING  OF  LEATHER. 


should  then  be  allowed  to  dry,  and  the  process  finished 
in  the  same  way  as  with  sleeked  leather,  except  that  a 
stretching-tool  of  copper  is  used  instead  of  one  of  iron, 
which  might  spot  or  soil  the  surface.  After  the  skin  is 
thoroughly  dry,  a  color  made  with  French  berries  is 
applied  on  the  hair  side.  Six  hides  may  be  colored  with 
two  grammes  of  berries,  which  quantity  is  to  be  placed 
in  a  litre  of  beer.  The  color  should  be  laid  on  with  the 
utmost  care,  so  as  to  secure  a  uniform  coating,  and  also 
as  briskly  as  possible,  otherwise,  the  skin  will  be  spotted 
or  discolored. 

"After  coloring  the  skins,  they  are  to  be  exposed  to  dry 
in  the  open  air,  avoiding  the  direct  heat  of  the  sun, 
which  would  cause  the  oily  matter  to  penetrate  through 
to  the  hair  side,  and  to  discolor  its  surface.  The  bar- 
berry is  not  required,  but  it  is  sufficient  to  rub  the  skin 
until  it  becomes  dry  with  a  small  cloth  or  piece  of  linen, 
by  which  the  surface  is  rendered  sufficiently  smooth  and 
polished.  Some  curriers  do  not  even  color  skins  of  this 
kind,  but  content  themselves  with  smoothing  them. 

"  A  method  still  different  from  this  is  sometimes  fol- 
lowed. When  the  skins  meant  to  be  yellowed  have  been 
properly  prepared,  they  are  pommelled  to  make  the  in- 
equalities of  the  surface  disappear,  and  fulled  in  a  cask 
containing  clean  water  (Fig.  172).    They  are  then  placed 


Fig.  172. 


CURRYING  OF  LEATHER. 


487 


upon  a  marble  table  with  the  flesh  side  uppermost, 
again  replaced  upon  the  stone  with  the  hair  side  up  for 
stoning,  and  drawn  out  with  the  stretching-iron.  This 
should  be  pressed  down  very  firmly,  for  the  purpose  of 
stretching  the  leather,  and  of  making  it  compact  and  firm. 
They  are  then  dried  a  little,  and  again  and  again  treated 
with  the  stretcher  of  copper,  care  being  taken  to  dry 
them  well  after  each  dressing,  with  a  clean  woollen  cloth. 
After  this  linseed-oil  is  applied  to  the  hair  side,  and  a 
composition  of  equal  parts  of  fish-oil,  oil  scouring,  and 
fine  white  tallow,  melted  together  and  passed  through  a 
hair-cloth  sieve,  is  used  for  the  flesh  side. 

In  order  that  the  shoulders  and  legs  should  have  a 
uniform  color  with  the  body,  it  is  proper  to  apply  a  less 
amount  of  the  liquid  to  them.  After  this  oiling,  the 
skins  are  dried  by  hanging  them  upon  a  rod,  with  its 
ends  passed  through  the  tail  and  one  of  the  legs.  When 
dry,  they  are  placed  anew  upon  a  table  of  marble;  the 
flesh  side  is  forcibly  stretched  out  with  a  warm  stretching- 
iron,  for  the  purpose  of  cleaning  them  and  making  them 
compact.  The  hair  side  is  then  placed  upwards,  moist- 
ened with  a  little  clean  water,  treated  with  the  copper 
stretcher,  dried  carefully  with  a  clean  rag,  and  passed  over 
wdth  the  stretcher  once  more  before  the  final  drying. 
Sometimes  a  color  made  with  a  little  Brazil  wood,  yellow 
berries,  and  glue,  heated  together,  is  used.  This  color  is 
passed  rapidly  and  lightly  over  the  hair  side,  and  the 
leather  is  then  stretched  and  exposed  to  the  air  until 
perfectly  dry,  and  is  finally  sliclced  with  a  piece  of  glass, 
attached  to  a  handle  like  that  of  a  stretching-iron.  Skins 
prepared  is  this  way  are  higher  priced  than  tallowed 
leather,  and  are  chiefly  used  by  harness-makers. 


488 


CURRYING  OF  LEATHER. 


WHITE  LEATHER. 

This  kind  of  leather  is  used  chiefly  by  shoemakers  for  the 
uppers  of  large  shoes,  the  hair  side  being  placed  within. 
The  skins  are  not  worked  up  whole,  but  are  made  into 
square  hides  by  cutting  off  the  head  and  bellj'-pieces, 
which  J  being  too  thin  for  the  purposes  for  which  the 
leather  is  employed,  are  used  for  the  first  or  upper  soles. 

The  skins  are  first  well  dipped,  and  then  scraped  care- 
fully with  the  head-knife  without  being  shaved.  They 
are  then  treated  on  both  sides  with  the  oil  and  train-oil 
scourings,  dried,  beaten  out  with  the  feet,  trimmed  on 
the  borders,  pressed  and  pommelled  to  efface  the  creases. 
The  preparation  is  completed  by  pommelling  with  the 
cork,  so  as  to  smooth  the  flesh,  and  grain  the  hair  side. 

This  leather  should  be  well  stuffed,  each  skin  absorb- 
ing usually  three  and  a  quarter  pounds  of  oil  and  train- 
oil  scourings.  Some  curriers  confine  themselves  to  pom- 
melling these  skins  on  both  sides,  and  then  drying  them, 
asserting  that  they  are  finer  for  not  being  beaten. 

COMMON  RUSSET. 

Leather  of  this  quality  is  prepared  in  the  same  manner 
as  blackened  leather,  except  that  it  is  allowed  to  absorb 
grease  to  saturation,  so  as  to  increase,  as  much  as  possible, 
its  strength  and  pliability.  For  this  purpose,  after  the 
skins  have  been  tallowed  and  half  dried  in  the  air,  they 
are  imbued  with  train-oil  scourings  on  both  sides,  about 
one  pound  ten  ounces  being  used  for  each  skin.  This 
leather  preserves  nearly  its  original  color,  and  is  used 
chiefly  for  pump-valves,  mail-bags,  bellows,  and  for  other 
purposes  not  requiring  much  beauty  of  surface. 


CHAPTER  XLYII. 

CURRYINa  OF  CALF-SKINS. 

Sometimes  calf-skins  are  prepared  almost  in  the  same 
manner  as  neats-leather,  the  thickest  and  largest  of  them 
being  occasionally  used  for  the  same  purposes  as  square 
hides;  but  the  latter  being  commonly  employed  in  the 
manufacture  of  soles,  the  calf-skin  leather  being  only 
used  for  uppers,  and  being  consequently  required  to  pos- 
sess more  pliability  and  softness,  must  be  treated  by 
processes  differing  from  those  to  which  thick  leather  is 
subjected. 

OILED  CALF-SKINS. 

As  soon  as  the  skins  are  taken  from  the  pits,  they  are 
dried  immediately,  scraped  and  trodden  out  under  the 
feet,  and  then  oiled  on  both  sides.  Some  curriers  make 
use  of  warm  oil  in  winter.  The  mixture  of  equal  parts 
of  oil  and  train-oil  scouring  is  generally  used  as  in  the 
oiling  of  cow-skins;  but  if  the  train-oil  scouring  be 
very  clear,  it  can  be  employed  alone.  From  eleven  to 
thirteen  pounds  of  the  oil  are  commonly  required  for  a 
dozen  calf-skins  weighing  from  thirty-three  to  forty 
pounds,  though  experience  alone  will  enable  the  work- 
man to  judge  of  the  amount  which  the  skins  are  capable 
of  absorbing  without  injury.  The  application  of  an 
32 


490 


CURRYING  OF  CALF-SKINS. 


excess  of  fatty  matter  should  generally  be  avoided,  as  it 
tends  to  make  the  leather  too  soft  and  flabby.  Skins, 
which  have  been  exposed  too  long  in  the  lime-vats,  do 
not  take  up,  or  retain  as  much  oil  as  those  which  have 
not  been  thus  injured.  After  having  been  oiled,  the 
skins  are  dried  and  generally  are  dressed  and  softened 
V  by  beating  with  the  feet,  and  bringing  out  the  grain  in 
the  usual  manner.  The  mode  of  preparation,  however, 
varies  with  the  uses  for  which  the  skins  are  intended ; 
those  which  are  to  be  waxed,  or  converted  into  grained 
or  stamped  leather,  not  being  worked  with  the  feet. 

In  order  to  cleanse  and  soften  the  leather,  and  to  pre- 
pare the  hair  side  for  the  reception  of  the  black,  a  brush 
is  dipped  in  a  solution  of  potash  made  by  dissolving 
rather  more  than  a  pound  of  potash  in  a  bucket-fall  of 
water,  and  is  passed  over  the  surface.  A  stronger  solu- 
tion might  injure  the  leather,  but  one  of  the  strength 
indicated  is  sufficient  to  combine  with  the  excess  of  oil 
upon  the  surface,  converting  it  into  soap,  and  enabling 
the  coating  of  black  to  adhere  more  readily  to  the  sur- 
face. This  operation  completed,  the  blacking  liquid, 
which  has  already  been  spoken  of,  is  applied  at  once, 
care  being  taken  not  to  lay  on  a  large  enough  quantity 
to  penetrate  below  the  surface  of  the  leather.  The  skins 
are  then  pommelled  from  head  to  tail  with  a  medium- 
sized  pommel,  used  with  four  parts  of  oil  and  one  of 
train-oil  scouring,  in  order  to  smooth  down  the  long 
ridges  which  traverse  the  leather  in  different  directions. 
A  second  coat  of  black  is  then  applied,  and,  if  necessary, 
the  leather  is  again  charged  with  the  same  oily  mixture, 
after  which  it  is  thoroughly  dried  by  exposure  to  air. 
It  is  then  trodden  out,  pommelled  on  both  sides,  pared 
down  on  the  borders  with  the  head-knife,  and  scraped 
with  the  round-knife.    To  complete  the  preparation,  it 


V 

CURRYING  OF  CALF-SKINS.  491 

is  pommelled  with  the  cork,  and  lightly  rubbed  over  upon 
the  grain  with  fish-oil,  in  order  to  deepen  the  color,  the 
appearance  of  which  the  previous  working  may  have 
injured. 

Another  method  is  sometimes  followed.  The  skins, 
wdien  dry,  after  oiling,  are  soaked  in  a  tub  until  suf- 
ficiently damp,  without  being  thoroughly  penetrated  by 
moisture,  and  are  then  pommelled  lengthwise  and  blacked. 
After  this,  they  are  pommelled  crosswise,  blacked  a  se- 
cond time,  charged  with  the  oily  mixture  mentioned 
above,  dried  thoroughly,  and  finally  worked  with  the 
pommel  from  head  to  tail,  and  oiled  as  before. 

TALLOWED  CALF-SKINS. 

A  large  proportion  of  the  calf-skins  used  are  oiled;: 
but  those  which  are  tallowed  are  much  less  liable  to  be 
penetrated  by  moisture.  To  prepare  them,  the  dry  skins- 
are  sprinkled  with  water  from  a  brush  and  are  scraped 
with  a  dull  knife,  or  with  the  stretching-iron,  unless  it 
is  desirable  to  diminish  their  thickness  by  paring.  The 
head  is  then  pared  down  with  the  head-knife  as  far  as 
the  junction  of  the  neck,  and  the  body  is  lightly  fleshed 
with  the  same  instrument,  the  surface  being  well  moist- 
ened to  prevent  the  knife  from  entering  too  deeply.  The 
skins  are  then  dried  and  pommelled  upon  the  flesh  with 
a  large  pommel,  and  upon  the  grain  with  the  cork,  in- 
stead of  using  pumice-stone,  which  was  formerly  em- 
ployed. They  are  then  tallowed  in  the  same  manner  as 
cow-skins,  dried,  worked  und^r  water,  pommelled,  and 
blackened  twice;  after  which,  they  are  pommelled  again, 
and  polished  or  rubbed  upon  the  grain  side  with  clear  oil. 
From  thirteen  to  sixteen  and  a  half  pounds  of  tallow  are 


492 


CURRYING  OF  CALF-SKINS. 


required  for  a  dozen  calf-skins  weighing  from  forty-two 
to  forty-four  pounds. 

These  skins  are  used  by  harness-makers  and  saddlers 
for  the  covers  of  horse-collars  and  other  purposes.  Thej 
are  also  employed  in  the  manufacture  of  thick  shoes^  and 
to  cover  trunks,  chairs,  and  tables. 

ENGLISH  CALF-SKINS. 

The  best  kinds  of  skins  are  selected  for  the  prepara- 
tion of  this  kind  of  leather,  and  the  processes  employed 
in  its  manufacture  are  similar  to  those  by  which  the  cow- 
skins,  intended  for  corresponding  purposes,  are  prepared. 
The  skins  are  tallowed  upon  the  flesh  side,  but  only  a 
small  quantity  of  grease  is  used,  so  that  the  leather  may 
not  be  penetrated  by  it,  and  this  and  the  succeeding 
manipulations  must  be  conducted  with  the  greatest  skill 
and  care,  in  order  to  avoid  injuring  or  soiling  the  sur- 
faces. 

The  thicker  skins  are  curried  white  for  the  uppers  of 
thick  shoes,  while  the  thinner  ones  are  used  for  thin  soles. 
Formerly,  the  white  leather  of  this  sort  was  used  for 
heel-rands.  The  skins  are  slightly  moistened,  pommelled 
in  every  direction,  and  after  being  oiled  and  thoroughly 
cleaned,  should  be  shaved  down  on  the  borders,  pared 
from  tail  to  head,  worked  two  together,  with  their  flesh 
sides  in  contact,  until  soft,  and  then  pommelled,  scraped 
with  the  round-knife,  and  passed  over  with  the  cork. 
The  greatest  care  should  be  taken  in  all  these  operations, 
to  avoid  scraping  or  scratching  the  surfaces,  which  are 
much  more  liable  to  receive  injury  than  those  of  neats- 
leather.  If  any  of  the  skins  are  found  to  have  been 
taken  from  stillborn  calves,  injury  to  them  is  avoided 


CURRYING  OF  CALF-SKINS. 


493 


by  passing  them  through  tan-liquor  and  exposing  them 
again  for  a  time  in  the  pits, 

WAXED  SKINS. 

This  kind  of  leather  has  only  been  prepared  during 
the  last  forty  years,  yet  so  great  a  degree  of  perfection 
has  been  attained  in  its  manufacture  that  it  is  now  very 
generally  used  for  the  legs  of  boots,  and  for  men's  and 
women's  shoes. 

The  heads  and  ends  of  the  extremities  of  skins  about 
to  be  converted  into  it,  are  first  cut  off,  and  the  leather 
is  then  moistened,  fleshed,  and  pared  so  as  to  be  perfectly 
uniform  throughout ;  being  reduced  to  the  thickness 
suitable  for  the  purposes  for  which  it  is  required.  It  is 
then  deposited  in  a  tub-full  of  water,  and  is  beaten  with 
a  rammer  or  pestle,  and  then  scraped  upon  a  marble  or 
wooden  table  with  the  slate,  first  upon  the  flesh,  and  af- 
terwards upon  the  hair  side.  After  this  proceeding,  it  is 
washed,  scraped  with  the  stretching-iron,  and  partially 
dried.  When  the  proper  degree  of  desiccation  has  been 
arrived  at,  it  is  worked  again  with  the  slate  and  stretch- 
ing-iron, only  upon  the  hair  side,  and  is  then  oiled  on 
both  sides ;  a  mixture  of  oil  and  of  train-oil  scouring  being 
applied  to  the  flesh,  and  clear  oil,  or  a  combination  of 
oil  and  tallow,  made  thick  enough  not  to  spread  beyond 
the  place  upon  which  it  is  deposited,  upon  the  hair  side. 
This  latter  mixture  is  a  very  suitable  application  in  sum- 
mer, when  oil  alone  is  almost  too  fluid.  As  soon  as  the 
leather  has  imbibed  a  suflicient  quantity  of  oily  matter, 
it  is  dried  and  thoroughly  cleaned  and  smoothed  upon 
marble,  or  a  smooth  table,  by  the  use  of  a  hot  stretching- 
iron.    It  is  then  pommelled  from  head  to  tail,  and  from 


494 


CURRYING  OF  CALF-SKINS. 


the  quarters;  is  placed  on  the  horse  (Fig.  173),  and 
cleaned  with  the  head-knife^  and  rubbed  across  with  the 
cork. 


Fiff.  173. 


After  these  preliminary  operations^  the  leather  is 
ready  to  receive  the  composition,  which  must  be  applied 
with  the  greatest  care  and  exactness,  so  as  to  secure  per- 
fect uniformity  of  surface  and  of  color,  either  extreme  of 
applying  too  much  or  too  little  being  avoided,  so  that  on 
the  one  hand  the  leather  may  not  be  entirely  penetrated 
by  the  fatty  substances,  and  on  the  other  that  the  color- 
ing material  may  be  just  sufficient  in  quantity  to  blacken 
the  whole  surface. 

The  composition  is  applied  cold  upon  the  flesh  side  with 
a  brush,  and  is  prepared  by  melting  tallow,  and  mixing  it 
thoroughly  with  enough  oil  and  lampblack  to  give  it  the 
proper  color  and  such  a  degree  of  consistence  that  it  shall 
neither  be  too  thick  nor  too  thin  to  be  applied  in  the  cold 
state.  For  this  purpose,  the  ingredients  may  be  mixed 
together  in  the  proportion  of  one  pound  of  lampblack  to 
twelve  of  oil  and  six  of  tallow.  When  this  mixture  has 
been  smoothly  and  uniformly  applied,  the  leather  is 
placed  upon  the  table,  and  any  inequalities  which  may 
exist  upon  its  surface,  are  smoothed  down  or  removed  by 
passing  the  flat  of  the  hand  over  it,  after  which  it  is 
cleaned  with  a  brush. 

A  second  coating  is  now  applied  above  the  first,  but 


CURRYING  OF  CALF-SKINS. 


495 


of  a  different  mixture,  made  by  thoroughly  incorporating 
together  (by  grinding  and  not  by  melting)  two  parts  of 
glue  and  one  part  of  tallow.  This  is  put  on  with  a  brush 
in  the  same  manner,  and  with  the  same  precautions  as 
the  first  one,  being  smoothed  with  the  hand,  and  at  last 
slicked  over  with  the  lump  of  glass.  Still  another  ap- 
plication is  made  to  finish  the  preparation  of  the  leather, 
and  this  consists  in  sponging  lightly^  the  whole  blackened 
surface  so  as  barely  to  moisten  it  with  glue. 

After  this  the  skins  are  dried  without  exposure  to 
the  sun. 

Calf-skins  prepared  in  this  manner  acquire  a  degree  of 
softness  and  suppleness  which  is  not  equalled  by  that  of 
any  other  kind  of  leather,  and  they  have  been  much  em- 
ployed in  the  manufacture  of  the  legs  of  boots  and  of 
men's  and  women's  shoes. 

GRAINED  CALF-SKINS. 

The  skins  selected  for  the  manufacture  of  this  kind  of 
leather  are  first  moistened ;  and  after  the  heads  are  pared 
down  in  order  to  equalize  the  thickness,  they  are  pom- 
melled from  tail  to  head,  placed  on  the  table,  and  scraped 
with  the  stretching-iron.  They  are  next  beaten  with  the 
pestle  in  a  tub  of  water ;  then  smoothed  out  upon  the 
marble  slab  on  both  sides,  in  order  to  reduce  tlie  natural 
grain  of  the  leather,  and  dried  until  they  have  lost  the 
greater  part  of  their  moisture.  The  blacking,  of  which 
we  have  already  given  the  composition,  is  then  applied 
upon  the  hair  side,  the  skins  are  again  smoothed  out,  and 
oiled  upon  both  sides.  They  are  dried,  and  deprived  in 
the  usual  manner  by  means  of  potash  or  lye  of  the  ex- 
cess of  oil  upon  the  surfaces,  and  are  then  smoothed 
upon  the  grain  with  the  stretching-iron.    In  order  to 


496 


CURRYING  OF  CALF-SKINS. 


furrow  the  surface  with  the  grain,  the  leather  is  then 
placed  upon  the  table  with  the  hair  side  up,  and  is  pom- 
melled first  crosswise,  and  then  from  tail  to  head,  taking 
care  that  the  lines  or  grooves  which  correspond  in  di- 
rection shall  be  perfectly  parallel.  For  this  purpose  a 
pommel  is  used  with  from  forty-five  to  fifty  teeth  to  the 
inch. 

Another  coating  of.  black  is  now  applied,  and  when 
this  has  been  absorbed  b}^  the  surface,  oil  and  train  oil 
scouring  are  brushed  over  in  suflRcient  quantity  for  the 
requirements  of  the  leather,  which  is  then  dried.  The 
hair  side  is  then  pommelled  in  the  same  manner,  and  in 
the  same  directions  as  before.  The  borders  are  pared 
upon  the  horse  with  the  round-knife,  any  injury  to  the 
form  of  the  grained  surface  being  avoided,  and  finally  a 
light  coating  of  pure  and  clear  oil  is  spread  over  it. 

CALF-SKIN  LEATHER  FOR  BELTS. 

For  preparing  this  leather,  the  head  and  extremities 
are  cut  off,  the  skins  are  soaked  in  a  tub  until  sufficiently 
wet,  and  then  shaved  upon  the  horse  with  the  head- 
knife  until  they  are  of  equal  thickness  throughout.  They 
are  then  beaten  in  a  trough  with  the  pestle  or  rammer, 
dried,  and  lightly  greased  upon  the  flesh  side  with  a  mix- 
ture of  equal  parts  of  tallow  and  of  oil,  and  upon  the 
hair  side  with  linseed  oil  alone.  After  this  operation, 
they  are  dried,  and  worked  upon  the  flesh  with  the 
stretching-knife,  and  sliclced  upon  the  grain  with  the 
glass.  Sometimes  a  grain  is  given  them  as  described  in 
the  last  section. 


CHAPTER  XLYIII. 


CURRYINO  OF  GOAT-SKINS. 


The  preparation  of  these  skins  requires  quite  as  much 
labor  as  that  of  calf-skins,  and  much  more  care  and  at- 
tention, on  account  of  their  greater  thinness.  The  currier 
receives  them  dried  after  having  been  oiled.  They  are 
first  softened  by  soaking  for  twenty-four  hours  in  a  vessel 
*  full  of  water ;  then  are  trodden  out  under  feet  three  at  a 
time,  and  scraped  on  the  horse  upon  the  flesh  side  only, 
with  a  blunt  knife.  When  nearly  dry,  they  are  oiled 
with  a  mixture  of  train-oil  scouring  and  oil,  each  dozen 
of  skins  weighing  from  twenty  to  twenty-two  pounds, 
requiring  from  six  and  a  half  to  nine  pounds  of  oil.  The 
oiling  having  been  completed,  they  are  again  trodden  out, 
scraped  clean,  and  pommelled  with  instruments  smaller 
than  those  used  for  calf-skins.  In  order  to  free  their 
surfaces  from  the  excess  of  oil,  and  to  soften  and  brighten 
them,  four  ounces  of  potash  are  dissolved  in  two  buckets- 
full  of  water,  and  the  solution  is  passed  lightly  over  the 
grain  side,  the  saponaceous  compound  formed  by  it  with 
the  oil  being  wiped  off.  The  quantity  of  potash  solu- 
tion prepared  will  be  sufficient  for  six  dozen  skins.  After 
this,  the  leather  is  grained  with  the  pommel,  and  is 
rubbed  with  a  bunch  of  straw  in  order  to  soften  the 
grain.    It  is  then  well  wiped  with  a  woollen  rag,  and 


498 


CURRYING  OF  GOAT-SKINS. 


blacked  with  a  mixture  made  of  one  ounce  of  powdered 
nutgalls,  one  pound  one  and  a  half  ounces  of  copperas, 
and  a  small  portion  of  Brazil-wood  boiled  for  a  short 
time  in  a  little  water,  and  then  stirred  about  in  a  bucket- 
full  of  the  same.  Six  skins  are  blacked  at  a  time,  and 
are  then  piled  upon  each  other  on  the  table  or  floor. 
The  pile  is  then  turned,  so  that  those  which  were  blacked 
first  become  uppermost,  and  each  one,  commencing  with 
the  one  on  top,  is  thoroughly  wiped  with  a  woollen  rag, 
and  is  then  stretched  to  dry. 

When  about  three-quarters  dry,  they  are  blacked  a 
second  time  with  a  hard  brush,  the  color  being  rapidly 
and  uniformly  distributed  over  the  surface,  and  they  are 
then  wiped  with  a  pad  or  roller  made  of  blanket-stuff, 
after  which  they  are  dried  in  the  air.  They  are  now 
pommelled  across  the  grain,  wiped,  moistened  with  sour 
beer  applied  upon  a  piece  of  listing,  and  rubbed,  to  reduce 
the  grain,  with  a  bunch  of  rushes  or  of  straw.  When 
this  operation  is  concluded,  the  borders  are  trimmed 
upon  the  horse,  the  skins  pared  with  the  round-knife, 
pommelled,  and  brightened  wdth  barberry-juice.  This 
last  operation  requires  care,  and  is  performed  by  passing 
the  listing,  dipped  in  the  polish,  rapidly  and  lightly  over 
the  surface  from  head  to  tail  end  across,  and  continuing 
to  rub  while  the  rag  remains  moist,  and  until  a  polish  is 
given.  The  roller  is  then  applied  equally  and  forcibly 
to  the  whole  surface  from  head  to  tail ;  the  skin  is  pom- 
melled lengthwise  and  across,  and  is  then  dressed  upon 
the  grain  with  pure  linseed-oil. 

It  was  formerly  the  custom  to  form  a  diamond-grain 
surf  ice  upon  goat-skins,  but  at  the  present  day  they  are 
usually  grained  in  straight  parallel  ridges,  formed  by 
pommelling  from  head  to  tail  alone. 


CURRYING  OF  GOAT-SKINS. 


499 


Another  method  of  preparing  goat-skins,  which  we 
proceed  to  describe,  has  been  proposed  by  Larue,  a 
Parisian  currier. 

Two  skins  are  sprinkled  at  a  time,  upon  the  hair  side, 
with  water  from  a  brush,  and  are  then  placed  upon  each 
other  with  their  hair  sides  in  contact,  and  after  being 
folded  up  into  a  cap-like  form,  are  beaten  with  the  feet 
or  with  the  mace.  They  are  then  pommelled  from  head 
to  tail  and  crosswise,  being  at  the  same  time  partially 
and  slightly  moistened  with  water  from  the  brush.  A 
dozen  or  more  skins  having  been  prepared  in  this  way, 
they  are  placed  in  a  tub  with  a  sufficient  quantity  of 
water  to  cover  them,  and  are  beaten  out  with  the  mace 
or  rammer,  after  which  they  are  stretched  out  smooth 
upon  the  marble  with  a  stretching-iron,  and  dried  par- 
tially. The  hair  sides  are  then  washed  over  with  a  weak 
solution  of  potash,  the  skins  are  scraped  upon  the  flesh 
with  the  stretcher,  rubbed  over  with  a  bunch  of  straw, 
stretched  again,  and  wiped  with  a  piece  of  woollen  cloth 
before  being  blacked.  To  make  the  color,  one  ounce 
one  and  a  half  drachms  of  powdered  nutgalls,  and  one 
pound  one  ounce  ten  drachms  of  copperas,  are  boiled  in  a 
sufficient  quantity  of  water  until  nearly  dissolved,  when 
the  mixture  is  thrown  into  a  bucket-full  of  water;  a  little 
Brazil  wood  is  added,  and  the  whole  is  well  stirred. 
This  is  lightly  spread  with  a  brush  over  the  hair  sides, 
and  the  skins  are  then  dried. 

In  a  variation  from  this  method,  sometimes  adopted, 
the  skins  are  moistened  with  a  solution  of  potash  instead 
of  simple  water. 

When  dry,  a  second  coat  of  color  is  applied  to  the 
skins  with  a  hard  brush  made  of  hog's  bristles,  rapidly 
passed  over  the  surfaces,  and  pressed  upon  them  with 


500 


CURRYING  OF  GOAT-SKINS. 


considerable  force.  After  this,  the  hair  sides  are  wiped 
with  a  woollen  cloth  made  into  a  pad  or  roller,  and  are 
pommelled  lengthwise.  The  edges  are  then  pared  upon 
the  horse  with  the  head-knife,  the  leather  is  scraped  and 
wiped  again,  and  finally  pommelled  either  so  as  to  pro- 
duce parallel  grooves  or  quadrilateral  figures,  the  former 
being  generally  preferred  in  goat-skins.  The  blackened 
surfaces  are  finally  polished  by  rubbing  them  with  a 
piece  of  cloth  or  list  dipped  in  barberry -juice,  and  after 
being  smoothed  by  the  roller,  are  oiled  upon  the  hair 
side  with  pure  linseed-oil,  which  completes  the  opera- 
tion. 

Morocco  and  fancy-colored  goat-skins,  after  being  dyed, 
require  to  be  curried  in  order  to  bring  them  to  their 
original  suppleness.  Those  which  are  intended  for  shoe- 
makers' use,  require  the  utmost  amount  of  pliability, 
and  after  being  thinned  on  the  flesh  side,  are  rubbed 
over  with  the  polisher,  and  then  grained  on  the  flesh  side 
with  a  leaden  or  wooden  pommel,  channelled  on  the  sur- 
face with  fine  parallel  grooves.  Finally,  they  are  reglazed 
with  the  polisher,  and  then  rubbed  over  with  a  cork- 
pommel. 

Pocket-book  and  case  leather,  in  general,  require  to  be 
thinned  evenly  like  the  above,  then  slightly  moistened, 
smoothed  on  the  table  by  stretching,  and  dried  again. 
The  grain  is  imparted  by  passing  them,  w^hen  in  a  moist 
state,  several  times,  in  opposite  directions,  between  cy- 
linders which  revolve  nearly  in  contact.  • 

Bookhout  and  Cochen,  of  New  York,  have  invented  a 
machine  for  smoothing,  graining,  and  polishing,  simulta- 
neously, which  does  its  work  effectively  and  with  dis- 
patch. Below  are  two  figures  which  represent  the 
machine  itself,  in  perspective,  and  the  sliding  head  in 


CURRYING  OF  GOAT-SKINS. 


501 


side  elevation.    In  Fig.  Hi,  A  A  A,  is  the  framework, 

Fig.  174. 


and  a  skin  of  leather  passing  over  the 
rollers  C  which  are  made  to  revolve 
by  means  of  a  ratchet-wheel  fastened 
to  the  back  end  of  the  roller.  H  H  is 
the  upper  section  of  sliding  head  attached 
to  the  connecting  rod  /,  whence  it  derives  its  backward 
and  forward  motion;  and  II,  are  the  ways  on  which  it 
runs.  These  ways,  as  well  as  the  clasps  0  G,  and  the 
feeding  rollers,  are  parallel  with  the  motion  of  the  finish- 
ing tools  a  a,  which  are  made  of  wood,  metal,  glass, 
stone,  or  horn. 

This  rolling-mill  w^ill  finish  about  three  dozen  skins  per 
Jioiir,  whereas  the  same  number  would  be  a  full  day's 
work  for  an  expert  hand-worker.  It  also  answers  for 
rolling  heavy  leather,  and  will  smooth  from  forty  to 
sixty  sides  per  hour. 


CHAPTER  XLIX. 


RED  LEATHER. 

This  kind  of  leather  was  very  largely  prepared  in 
former  times,  but  is  replaced,  in  a  great  measure,  at  the 
present  day,  by  Morocco  sheep  leather ;  some  of  it,  how- 
ever, is  still  manufactured  of  a  finer,  but  less  permanent 
color  than  Russia  leather,  and  without  its  odor.  These 
skins  have  an  average  weight  of  twelve  pounds,  and  are 
used  by  harness,  coach,  and  trunk-makers. 

Fine  clean  skins,  with  a  uniform  smooth  surface,  and 
which  have  not  been  tallowed,  but  have  only  received  a 
light  coat  of  pure  oil,  are  selected  for  this  purpose.  They 
are  dipped,  pared,  beaten  under  water,  and  dried  in  the 
ordinary  way,  and  coated  with  pure  oil  on  the  hair,  and 
a  mixture  of  oil  and  oil-scouring  upon  the  flesh  sides, 
about  half  a  pound  of  each  being  used  for  the  purpose. 
A  solution  of  alum  in  water,  which  probably  acts  as  a 
mordant  for  fixing  the  color,  is  then  rubbed  over  the 
hair  side  from  head  to  tail  with  a  brush,  and,  while  still 
wet  with  it,  the  skins  are  softened  by  beating  and  rub- 
bing them,  after  which  they  are  pommelled,  dried,  and 
rubbed  with  a  cork. 

In  order  to  prepare  the  color,  about  ten  pounds  of 
quicklime  are  slaked  and  dissolved  in  four  buckets-full 
of  water.  On  the  third  day,  the  clear  liquor  is  decanted 
off,  and  the  half  of  it  is  emptied  into  a  copper  boiler. 


RED  LEATHER. 


503 


In  order  to  make  two  buckets-fall  of  color,  eight  and 
three-quarter  pounds  of  Brazil  wood  are  then  thrown 
into  this  lime-water,  and  the  mixture  is  rapidly  boiled 
with  constant  stirring,  until  reduced  to  half  the  original 
quantity.  It  is  then  removed,  and  the  remainder  of  the 
lime-water  is  emptied  into  the  boiler  and  evaporated  to 
one-half,  when  the  first  liquid  is  again  thrown  in  the 
boiler;  and,  after  adding  nine  drachms  of  powdered  coch- 
ineal, the  whole  is  boiled  for  a  short  time.  While  still 
boiling,  a  lump  of  lime,  of  the  size  of  an  egg,  is  thrown  in, 
and  the  boiler  is  then  removed  from  the  fire  and  allowed 
to  cool. 

This  quantity  of  color  is  sufficient  for  reddening  eigh- 
teen or  twenty  skins.  It  is  applied  thoroughlj^  upon  the 
surfaces,  being  rubbed  over  in  the  direction  from  head 
to  tail.  The  skins  are  then  partially  dried,  coated  a 
second  time,  entirely  dried,  and  finally  pommelled  from 
head  to  tail.  After  this,  they  are  brushed  over  a  third 
time  with  the  color,  to  which  the  white  of  an  egg  has 
been  added,  are  dried,  greased  with  an  oiled  woollen  rag, 
and  slicked  smoothly  with  the  glass,  which  is  generally 
made  like  a  muller.  They  are  finally  rubbed  over  in 
the  usual  way  with  barberry-juice,  dried,  and  again 
strongly  slicked. 

Another  process  for  reddening  leather  has  been  given 
by  Dessables.  In  this,  one  pound  one  and  a  half  ounces 
of  alum  is  dissolved  by  boiling  in  a  pint  and  a  half  of 
water,  and  the  solution  is  poured  into  a  large  earthen 
pan,  and  mixed  with  six  and  a  quarter  pints  of  clean 
water.  This  quantity  is  sufficient  to  alum  three  dozen 
calf-skins. 

Three  and  one-quarter  pounds  of  Brazil  wood,  and  a 
lump  of  fresh  lime,  of  the  size  of  an  egg,  are  then  boiled 
for  five  or  six  hours  in  four  gallons  of  water. 


504 


RED  LEATHER. 


The  skins,  being  in  the  same  condition  as  before  being 
blacked,  are  rubbed  over  with  a  piece  of  wool  dipped  in 
the  alum  liquor,  and  after  being  well  dried,  receive 
three  coats  of  the  color  in  the  same  manner  as  before 
described. 


CHAPTER  L. 


FAIR  LEATHER. 

This  leather,  used  for  the  soles  of  ladies'  shoes,  is  made, 
preferably,  from  hides  tanned  with  Spanish  oak.  After 
having  been  soaked  and  scoured,  they  are  separately 
spread  upon  a  clean  table  and  sponged  on  the  grain  side 
with  the  following  mixture,  reduced  by  dilution  with 
water : — 

The  proportions  for  nine  and  a  half  pints,  which  is 
the  quantity  required  for  twenty-five  sides,  are — 

Crystallized  chloride  of  tin  . 
Muriatic  acid,  free  from  iron 
Sulphuric  ether  . 
Alcohol  .... 
Water       .       ,       .  , 

The  tin  salt  is  placed  in  a  blue  stone  jar  with  the 
acid,  and  the  whole  is  stirred  until  perfect  solution  is 
effected.  The  ether,  alcohol,  and  water  are  then  added 
and  stirred  in  successively. 

This  process,  patented  by  Prof.  J.  C,  Booth,  of  Phila- 
delphia, is  founded  strictly  upon  scientific  principles. 
The  tin-salt  and  acid  are  the  bleaching  agents,  while 
the  alcohol,  ether,  and  water  are  diluents  as  well  as  pro- 
tectives  against  any  destructive  tendency  of  the  former. 
Its  whitening  effect  extends  throughout  the  hide,  and  is 
33 


8  ounces 

4  fluidounces 

8 

32  " 
40  " 


506 


FAIR  LEATHER. 


not  limited  merely  to  the  surface.  After  the  application 
of  the  liquor,  the  leather  is  oiled,  dressed,  and  rolled,  as 
in  the  usual  currying  process. 

This  mixture  is  not  appUcable  to  leather  tanned  with 
black  oak-bark,  as  it  colors  it  yellow. 


CHAPTER  LI. 


WATER-PROOF  DRESSINGS. 

This  chapter  contains  an  account  of  certain  processes 
by  which  leather  is  said  to  be  rendered  water-proof;  but, 
however  efficient  they  may  be,  it  is  doubtful  whether 
any  such  quality  can  be  permanently  imparted  by  the 
proposed  treatment. 

1.  PATENTED  PROCESS  OF  MESSRS.  SMITH  AND  THOMAS. 

The  leather,  which  it  is  intended  to  render  impervious, 
is  first  soaked  for  twenty-four  hours  in  water,  is  then 
pressed  between  iron  cylinders  in  order  to  remove  the 
greater  part  of  the  moisture,  and  after  being  thoroughly 
dried  by  exposure  to  the  air  during  some  days,  is  steeped 
in  the  following  mixture : — 


Linseed  oil        ....  4  pints 

Olive  oil    .       .  •      .       .       .  2  " 

Oil  of  turpentine       ...  1  pint 

Castor-oil   2  pints 

Yellow  wax      .       .       .       .  8  ounces 

Pitch   i  " 


The  ingredients  are  mixed  and  boiled  together  in  a 
large  earthen  pan,  and,  while  in  a  state  of  ebullition, 
the  leather  is  soaked  in  the  mixture  for  a  longer  or 


508 


WATER-PROOF  DRESSINGS. 


shorter  time,  according  to  its  nature ;  sole  leather  being 
allowed  to  soak  in  it  for  twenty  minutes,  and  cow  and 
calf  skins,  the  legs  of  boots,  &c.,  for  ten  minutes  or  more. 
After  being  removed,  they  are  drained  and  then  pressed 
between  cylinders  covered  with  copper.  They  are  then 
partially  dried  in  a  room  in  which  a  temperature  of  from 
88°  to  100°  Fahrenheit  is  maintained;  are  pressed  out 
again,  and,  finally,  entirely  dried  at  the  same  tempera- 
ture as  before. 

2.  PATENTED  PROCESS  OF  M.  NENORY  FOR  PREPARING  ELASTIC 
AND  IMPERVIOUS  LEATHER. 

Seventy-five  pounds  of  linseed  oil,  and  nine  pounds 
twelve  ounces  of  litharge,  are  first  boiled  with  moderate 
heat,  until  the  whole  is  reduced  to  two-thirds  of  its  ori- 
ginal quantity,  and  the  oil  thus  prepared  is  set  aside  for 
use. 

3  pounds  12  ounces  of  old  linseed  oil, 

8  ounces  of  white  wax, 

2  pounds  12  ounces  of  glue, 

2  ounces  of  verdigris,  and 

2  pounds  of  water  are  then  mixed  together  and 
moderately  heated  in  an  iron  pot,  with  frequent  stirring, 
over  a  slow  fire,  until  the  ingredients  are  united  in  a 
uniform  mixture. 

50  pounds  of  the  oil,  prepared  as  above  directed, 
1  pound  8  ounces  of  the  second  mixture,  above  de- 
scribed, 

5  pounds  of  yellow  wax, 

6  pounds  8  ounces  of  oil  of  turpentine, 
1  pound  of  balsam  of  Peru, 

1  pound  of  oil  of  thyme,  and 

3  pounds  of  white  rosin,  are  then  melted  together 


WATER-PROOF  DRESSINGS. 


509 


over  a  slow  fire,  without  being  boiled,  and  when  the 
mixture  of  the  ingredients  is  complete,  the  composition 
is  poured  into  jars  or  bottles,  to  be  preserved  for  use. 

When  required  for  use,  one  of  the  jars  containing  the 
mixture  is  placed  near  a  fire,  in  order  to  render  it  suffi- 
ciently fluid  for  application  to  the  leather.  The  boots  or 
shoes  which  are  to  be  made  water-proof,  are  then  well 
cleaned  and  brushed,  and  are  rubbed  over  with  a  sponge 
or  brush  dipped  in  the  composition ;  the  operation  being 
conducted  either  in  the  hot  sunshine,  or  near  a  fire. 
This  is  repeated  as  soon  as  the  articles  are  dry,  until 
they  are  saturated  with  the  mixture,  and  if  any  excess 
of  it  remains  upon  the  surface,  it  is  to  be  rubbed  off  with 
a  thick  cloth.  By  this  operation,  boots  or  shoes  are  said 
to  be  rendered  completely  water-proof,  and  to  acquire  an 
increase  of  suppleness,  elasticity,  and  durability. 

3.  PROCESS  OF  M.  J.  DEANE,  PATENTED  IN  1844. 

First  Preparation, — 1.  Take  of  linseed  oil,  neats-foot  oil, 
and  rape-seed  oil,  265  gallons,  and  reduce  by  boiling  to 
23  gallons. 

2.  A  quantity  of  beef  or  mutton  suet,  rendered  by 
melting,  straining,  boiling  with  clear  water,  straining 
again,  and  separating  from  the  last  particles  of  water  by 
pressing  between  the  folds  of  bibulous  material. 

3.  37  pounds  8  ounces  of  the  suet  thus  prepared,  and 
the  same  quantity  of  fresh  wax  are  melted  and  stirred 
together  with  the  oil  No.  1,  until  mixed,  at  a  temperature 
of  about  150°  Fahrenheit. 

4.  2  pounds  3  ounces  and  9  drachms  of  caoutchouc 
in  shreds,  are  dissolved  in  16  pints  and  12  ounces  of 
rectified  oil  of  turpentine,  at  a  temperature  of  248° 


510 


WATER-PROOF  DRESSINGS. 


Fahrenheit,  the  operation  being  conducted  over  a  sand- 
bath. 

5.  11  pounds  half  an  ounce  of  Burgundy  pitch  are 
melted  on  a  sand-bath,  at  a  temperature  of  194°  F.,  in 
22  pints  6  ounces  of  rectified  oil  of  turpentine.  The 
solution  of  caoutchouc,  No.  4,  is  then  mixed  with  it,  and 
the  whole  is  allowed  to  cool  until  it  attains  the  tempera- 
ture of  158°  F.,  when  it  is  mixed  by  stirring  until  the 
whole  is  cold,  with  the  melted  fat,  wax,  and  oil  No.  3. 

Second  Preparation, — 11  pounds  9  drachms  of  yellow 
rosin  are  dissolved  in  33  pints  12  ounces  of  rectified  oil 
of  turpentine,  by  heating  over  a  sand-bath,  at  a  tempera- 
ture of  200°  F.,  and  when  cooled  down  to  150°,  the  so- 
lution is  added  to  a  mixture  of  oil,  wax,  and  suet,  in  the 
proportions  directed  for  No.  3,  of  the  first  preparation. 

Third  Preparation. — 22 i  gallons  of  pure  whale  oil, 
and  16  i  pounds  of  caoutchouc  in  shreds,  are  heated  at  a 
temperature  of  from  190°  to  240°  F.,  until  the  latter  is 
perfectly  dissolved. 

Fourth  Composition. — 16  i  pounds  of  shreds  of  caout- 
chouc are  gently  boiled  over  a  sand-bath,  in  a  quantity 
of  oil  of  turpentine,  sufficient  to  cover  them,  until  they 
are  dissolved.  22  J  gallons  of  pure  cod-liver  oil,  or  whale 
oil,  at  a  temperature  of  194°  F.,  are  then  added.  When 
thoroughly  mixed,  the  heat  is  allowed  to  fall  to  150°, 
when  8  pounds  14  ounces  of  wax  are  added  to  the  mix- 
ture, and  the  whole  is  stirred  until  cold. 

The  first  two  of  these  compositions  are  intended  for 
the  preparation  of  skins  for  uppers,  and  the  last  two  for 
that  of  sole  leather,  and  both  kinds  of  leather  are  ren- 
dered by  them  more  flexible  and  durable,  and  perfectly 
water-proof 

The  portions  of  leather  intended  for  uppers,  are  placed 
side  by  side,  and  upright,  in  a  suitable  vessel  communi- 


WATER-PROOF  DRESSINGS. 


511 


eating  with  a  boiler.  Either  the  first  or  the  second  com- 
position is  then  placed  in  the  boiler  and  heated  to  a  tem- 
perature of  from  122°  to  212°  F.,  when  it  is  drawn  off 
into  the  vessel  containing  the  leather,  until  the  latter  is 
entirely  covered  with  it.  After  being  steeped  in  the 
mixture  for  two  or  three  hours,  the  leather  is  exposed 
to  a  partial  vacuum  in  an  air-tight  reservoir,  by  which 
the  composition  is  made  to  penetrate  its  substance,  and 
it  is  then  dried  in  a  current  of  warm  air.  The  first  com- 
position is  suitable  for  skins  properly  tanned  with  oak 
bark,  and  the  second  to  those  which  have  been  tanned 
imperfectly,  or  by  other  materials  than  bark. 

Thin  sole  leather  is  impregnated  with  the  third  com- 
position, and  the  thicker  kind  with  the  fourth.  The 
hides,  or  portions  of  them,  are  placed  upon  metal  plates, 
heated  to  104°  F.,  and  are  repeatedly  covered  with  the 
mixture  by  means  of  brushes  saturated  with  it.  They 
are  then  made  to  absorb  the  composition,  and  to  dry  at  the 
same  time,  by  exposure  to  a  partial  vacuum  and  currents 
of  rarefied  air  in  an  air-tight  chamber,  constructed  for  the 
purpose. 

Manufactured  articles  of  leather  are  prepared  by  warm- 
ing them,  smearing  them  with  any  one  of  the  above- 
described  compositions,  and  drying  at  a  moderately  ele- 
vated temperature. 

4.  CHEAP  AND  SIMPLE  METHOD  OF  MAKING  LEATHER 
WATER-PROOF. 

Two  pounds  of  tallow,  a  pound  of  hogs'  lard,  a  half 
pound  of  turpentine,  and  the  same  quantity  of  beeswax 
are  melted  together  in  an  earthen  pipkin.  The  boots 
and  shoes  are  dried  and  warmed,  and  the  composition  is 
well  rubbed  into  them,  with  a  piece  of  tow  dipped  into 


512 


WATER-PROOF  DRESSINGS. 


it;  the  articles  being  held  near  a  hot  fire  until  they  have 
imbibed  as  much  as  they  can  take  up.  This  mixture 
is  used  with  very  good  effect  by  sportsmen.  Another 
mixture  for  the  same  purpose,  which  is  much  used  by 
iishermen,  is  applied  in  the  same  way.  It  consists  of  a 
pound  of  beeswax,  a  half  pound  of  rosin,  and  the  same 
quantity  of  beef-suet. 

Jennings's  process 

Is  founded  upon  the  double  decomposition  of  metallic 
salts,  by  soluble  soaps.  The  patentee  dissolves  any  me- 
tallic soap  in  an  equal  quantity  of  raw  linseed  oil,  and 
immerses  the  leather  in  the  solution  at  225°.  When  the 
latter  has  become  cold,  the  leather  is  taken  out  and  dried 
by  exposure  to  air.  Forty-eight  hours  suffice  for  the 
whole  process. 

This  invention  is  also  applicable  to  canvas  and  simi- 
lar fabrics.  One  hundred  and  twelve  pounds  of  soft 
soap  being  dissolved  in  30  gallon-s  of  boiling  water,  the 
solution  is  then  heated  at  212°  F.,  with  56  to  66  pounds 
of  white  vitriol  (sulphate  of  zinc).  An  exchange  of 
bases  takes  place,  insoluble  oleate  of  zinc  and  soluble 
alkaline  sulphates  being  formed.  The  first  rises  to  the 
surface  of  the  liquor,  and  must  be  reboiled  in  fresh 
water  to  purify  it  of  all  soluble  matters. 

Five  pounds  of  pearlash  are  next  boiled  with  50  gallons 
of  raw  linseed  oil,  until  the  mixture  assumes  a  soapy  ap- 
pearance; and  to  it,  while  still  hot,  are  added,  and  well 
stirred  in,  2i  pounds  sugar  of  lead,  2  pounds  litharge,  4 
pounds  red  lead,  and  21  pounds  black  rosin.  The  whole 
is  boiled  for^n  hour  during  constant  stirring,  and  at  the 
end  of  that  time,  30  pounds  of  the  metallic  soap  are 
added.    The  mixture  is  subsequently  treated  with  2 


V 


WATER-PROOF  DRESSINGS. 


513 


gallons  of  a  liquor  made  by  dissolving  caoutchouc,  in  the 
proportion  of  24  ounces  to  one  gallon  of  spirits  of  tur- 
pentine. The  mixture  must  be  allowed  to  cool  to  160° 
F.,  and  it  may  then  be  applied  with  a  brush.  Two,  or 
at  most,  three  coats  suffice ;  but  there  must  be  a  sufficient 
interval  between  each  to  insure  perfect  drying. 

The  salts  employed  give  their  own  characteristic 
color  to  the  mixture :  for  example,  those  of  iron  impart 
a  brown,  and  those  of  zinc  and  lead,  a  white. 


• 


CHAPTEE  LII. 


JACOB  PERKINS'S  MACHINE  FOR  POMMELLING  AND 
GRAINING  LEATHER. 


Fig.  176,  side  view. 
Fig.  177,  front  view. 
Fig.  178,  plan. 


a.  Framework  held  together  by  bolts  with  nuts. 

h.  Large  horizontal  wooden  shaft,  its  iron  pivot  c  turn- 
ing in  the  copper  collars  d, 

e.  Four  wooden  arms  radiating  from  the  middle  of  the 
shaft  h,  and  curved  at  their  bases. 


POMMELLING  AND  GRAINING  LEATHER. 


515 


/.  Four  fluted  or  grooved  cylinders  of  lignum  vitas  wood, 
in  the  ends  of  the  wooden  arms.  The  grooves  are  near 
or  far  from  each  other,  according  to  the  grain  intended 
to  be  given  to  the  leather. 


Fig.  177. 
J" 


516 


POMMELLING  AND  GRAINING  LEATHER. 


g.  Two  iron  grooves  attached  to  each  of  the  arms,  and 
receiving  the  pivots  of  the  cylinders  /  in  their  extremi- 
ties; these  grooves  are  kept  in  place  by  the  guides  and 
slide  against  the  blocks  It,  Fig.  176. 

Fig.  176.  Springs  resting  against  the  lower  part  of 
the  base  of  the  grooves  and  by  their  elasticity  tending 
to  push  these  grooves  away  from  the  shaft  h, 

L  Screw  and  nut,  the  end  of  which  presses  to  th^ 
required  extent  upon  the  lower  end  of  the  groove  g. 
When  this  screw  is  tightened,  the  groove  presses  down 
the  spring,  and  approaches  the  shaft ;  when  loosened  the 
opposite  movement  takes  place. 

m.  Pieces  forming  a  support  or  frame,  and  curved  in 
the  form  of  arcs  of  the  circle  of  which  the  shaft  is  the 
centre,  so  as  to  allow  the  arms  to  revolve  freely.  This 
frame  should  be  very  firm,  and  supplied  with  a  surface 
of  hard  wood  for  the  cylinders  to  rotate  upon. 

n.  Circle  attached  by  bolts  to  the  arms,  and  serving  to 
strengthen  them. 

o.  Pulley  upon  the  shaft  h,  intended  to  receive  the  mo- 
tive power  by  means  of  a  band. 

The  leather,  when  prepared  in  the  ordinary  way,  and 
ready  to  be  grained  and  polished,  is  placed  upon  the 
wooden  table  or  frame  m,  and  the  shaft  h  is  turned. 
The  grooved  cylinders  /,  stamp  furrowed  surfaces  upon 
the  leather,  and,  owing  to  the  resiliency  of  the  springs, 
adapt  themselves  to  its  variations  of  surface  and  thick- 
ness. The  skin  is  moved  about  by  the  workman  so  that 
the  different  portions  shall  all  be  grained  in  the  required 
directions,  and  during  the  process,  the  surface  of  hard 
wood  m  is  from  time  to  time  moistened  with  water  or  oil, 
to  prevent  it  from  becoming  heated. 

The  cylinders  /,  in  the  course  of  their  revolution,  press 
against  brushes  which  keep  them  clean.    Upon  each  of 


POMMELLING  AND  GKAINING  LEATHER.  517 


their  axles  is  a  ratchet-wheel  with  a  catch  Fig.  176, 
the  object  of  which  is  to  prevent  them  from  revolving. 
When  the  grooves  of  the  cylinder  are  worn  out  at  one 
point,  they  can  be  renewed  by  turning  the  cylinder  round, 
so  as  to  present  a  new  part  of  its  circumference. 

The  shaft,  the  pulley,  the  arms,  and  the  circular  sup- 
port can  all  be  made  of  cast-iron  in  one  piece. 


CHAPTER  LIII. 


MACHINES  FOR  SPLITTINa  AND  SHAVINa  LEATHER. 

Leather  sides  and  skins  are  subjected  to  the  action 
of  these  machines,  either  to  render  them  smooth  and  of 
uniform  thickness  by  the  shaving  off  of  all  irregularities 
or  unevenness,  or  for  the  economical  purpose  of  convert- 
ing one  side  of  thick  leather  into  two,  and  rendering  the 
latter  serviceable  for  uses  to  which  in  their  original  thick- 
ness they  would  be  inapplicable. 

There  are  several  machines  for  splitting  leather,  the 
most  favorably  known  of  which  are  the  following : — 

Degrand's  Machine. — A  transverse  section  of  this  ma- 
chine is  shown  in  Fig.  179.    A  horizontal  knife  a,  longer 


than  the  greatest  width  of  a  skin,  is  fixed  upon  a  wooden 
table  B.    A  cast-iron  plate  h  is  set  in  the  table  in  front 


Fig.  179. 


SPLITTING  AND  SHAVING  LEATHER. 


519 


of  the  knife-blade,  and  is  intended  to  support  the  lea- 
ther c  at  the  desired  elevation,  its  position  being  regu- 
lated by  screws  and  nuts.  It  is  movable  in  every  direc- 
tion, being  supported  upon  four  springs.  Above  it,  a 
little  wooden  shelf  cZ,  which  is  pressed  upon  by  a  roller 
maintains  the  leather  in  close  contact  with  the  plate,  so 
as  to  flatten  and  stretch  it  thoroughly  before  it  is  exposed 
to  the  blade.  One  of  the  separated  surfaces  of  the  lea- 
ther, as  it  rises  over  the  knife,  is  attached  to  a  wedge- 
shaped  tongue,  which  projects  from  the  whole  length  of 
the  wooden  roller  c,  and  is  wound  up  upon  the  latter  as 
it  advances. 

The  leather  is  seen  in  the  figure  as  split  by  the  blade 
of  the  knife,  the  upper  portion  of  it  being  already  rolled 
upon  the  cylinder  c.  The  lower  half  passes  down  under 
the  knife  through  a  slit  in  the  table,  and  the  uncut  por- 
tion, which  is  about  to  be  exposed  to  the  action  of  the 
blade,  is  seen  resting  upon  the  table,  and  pressed  down 
by  the  upper  plate  d.  The  movement  of  revolution  is 
given  to  the  cylinder  by  a  winch  which  turns  a  pinion 
gearing  with  a  toothed  wheel  at  one  of  its  ends.  Two 
operations  are  required  to  split  the  leather,  one-half  of 
it  being  first  separated,  the  skin  being  then  unrolled  from 
the  cylinder,  turned,  and  the  spht  part  attached  to  it,  so 
that  the  other  half  may  be  in  like  manner  divided.* 

Giraudon's  Machine. — This  interesting  invention  has 
been  described  by  M.  Armengaud,  in  the  Puhlication  In- 

*  The  author  has  omitted  to  explain  the  mode  of  forcing  the  edge  of 
the  leather  upon  the  knife-blade,  by  which  the  first  part  of  the  incision 
is  effected.  The  process  can  only  be  rationally  understood  by  supposing 
that  a  longitudinal  incision  is  first  made  down  the  centre  of  the  skin 
extending  half  through  its  thickness,  and  that,  while  one  edge  of  the 
skin  is  attached  to  the  roller,  the  knife  is  accurately  engaged  in  the  bot- 
tom of  the  cut  previously  made. 


\ 


520  SPLITTING  AND  SHAVING  LEATHER. 


dustrielle  des  MacJdnes,  outils  et  appareils,  t.  vi.  liv.  9. 
The  machine  is  simple  in  construction^  operating  rapidly 
and  continuously  upon  the  skins  exposed  to  its  action, 
and  can  be  employed  either  for  the  purpose  of  dividing 
the  leather  into  thin  sheets  or  leaves,  or  for  that  of 
diminishing  and  equalizing  its  thickness. 

The  hide  or  skin  which  is  to  be  cut  is  placed  upon  the 
circumference  of  a  large  drum  or  cylinder  A  (Figs.  180, 


Fio;.  180. 


Fig.  181. 


SPLITTING  AND  SHAVING  LEATHER.  521 

181,  and  182),  carefully  turned  and  attached  to  three 
crosspieces  with  six  branches  or  spokes  b,  which  are  con- 
Fig.  182. 


nected  with  the  cast-iron  horizontal  shaft  c.  This  cylin- 
der is  hollowed  out,  as  seen  in  the  section  shown  in  Fig. 
183,  for  the  reception  of  a  kind  of  pincers  d  (Fig.  189), 
which  serve  to  support  the  extremity  of  one  of  the  de- 


rig.  183. 


34 


522 


SPLITTING  AND  SHAVING  LEATHER. 


t ached  portions  of  skin  against  the  edge  of  the  cylinder. 
For  this  purpose,  these  pincers  are  all  mounted  upon  the 
same  iron  axle  a,  which  rests  upon  small  supports 
fastened  to  the  cylinder,  and  they  are  kept  in  place  by 
a  flat,  angular  regulator. 

The  horizontal  shaft  c,  which  extends  on  each  side 
beyond  the  cast  framework  e,  carries  at  one  end  the 
larger  cog-wheel  f,  which  is  geared  with  the  endless 
screw  e  (Figs.  184  and  185),  situated  at  the  lower  part 


Fig.  184. 


Fig.  185. 


of  the  machine,  and  revolving  upon  the  axle  /,  the  slow 
movement  of  which  is  produced  by  means  of  the  wheel 


Fig.  187. 


Fig.  188. 


2^1 


Fig.  189. 
i> 


G,  the  endless  chain  and  the  pinion  h.  This  pinion 
turns  upon  the  cast-iron  shaft  h,  which 
is  made  to  revolve  by  means  of  a  strap 
passed  over  one  of  the  pulleys  i;  a  fly- 
wheel J  giving  the  necessary  uniformity 
to  the  motion.  A  roller  i,  at  the  end  of 
a  counterpoised  lever/,  presses  against  the 
endless  chain,  and  gives  it  the  proper 


amount  of  tension. 


SPLITTING  AND  SHAVING  LEATHER.  523 


The  shaft  h  is  elbowed  in  the  middle,  so  as  to  form  a 
crank  for  the  head  of  the  cast-iron  rod  k,  which  is 
articulated  at  its  other  end  with  the  middle  of  the  mov- 
able rabbit  or  carriage  L  (Figs.  183  and  186).  At  the 
base  of  this  is  attached  the  long  cutting  steel  blade  which 
is  inclined  a  little  in  direction  to  the  horizon,  and 
touches  the  exterior  of  the  cylinder  when  made  to  ap- 
proach it.  It  is  very  thin  and  of  an  undulating  form,  as 
shown  in  the  plan  (Fig.  187),  so  as  to  act  upon  the  leather 
like  a  saw,  the  teeth  of  which  are  rounded  off ;  by  which 
arrangement  it  cuts  more  easily  and  with  less  wear  of 
edge.  This  knife-blade  is  attached  to  the  base  of  the 
rabbit  by  means  of  an  iron  plate  m,  the  position  of 
which  can  be  accurately  adjusted  with  a  screw. 

The  movable  rabbit  or  carriage,  is  dove-tailed  into 
the  tops  of  two  cast-iron  supports  e,  which  compose  the 
framework.  The  grooved  plates  n  above  it,  prevent  any 
deviation  from  the  reciprocating  rectilinear  movement 
produced  by  its  connection  with  the  crank.  Thus  the 
same  shaft  h  which  moves  the  crank,  causes  the  revolu- 
tion of  the  lower  axle  /,  and  of  the  endless  screw,  by 
means  of  which  the  drum  upon  which  the  skin  is  wound, 
is  also  turned;  but  with  a  motion  exceedingly  slow,  when 
compared  with  that  of  the  crank  above,  and  the  knife 
connected  with  it.  The  ratio  of  size  between  the 
pinion  7i,  and  the  wheel  G  being  as  one  to  eight,  and  the 
large  wheel  f  having  244  teeth,  it  follows  that  the 
cylinder  only  turns  once  while  the  axle  /  and  the  end- 
less screw  are  making  244  revolutions,  and  the  main 
shaft  H  is  making  1952.  By  causing  the  main  shaft  to 
revolve  75  times  in  a  minute,  the  knife  is  made  to  cut 
the  leather  150  times,  so  that  a  skin  78.74  inches  in 
length  will  be  split  in  15  J  minutes. 

The  leather  is  maintained  in  close  contact  with  the 


524  SPLITTING  AND  SHAVING  LEATHER. 


cylinder  in  front  of  the  knife-blade,  by  the  pressure  of  a 
series  of  flexible  spring-keys  which  adapt  themselves  to 
its  irregularities  of  surface,  and  keep  its  uncut  edge 
firmly  pressed  down,  by  means  of  a  crosspiece  extending 
along  its  whole  breadth,  and  supported  by  projections 
upon  the  inside  of  the  framework.  A  strong  bar  g 
serves  to  support  the  other  ends  of  the  springs,  and  also 
assists  in  keeping  the  leather  applied  to  the  surface  of 
the  cylinder.  Two  grooved  uprights  are  adjusted  in 
rectangular  vertical  mortises  of  the  framework,  and  the 
screws  x,  in  their  lower  parts,  regulate  the  height  of  the 
bar. 

The  lower  separated  portion  of  the  split  leather  re- 
mains in  contact  with  the  cylinder  while  it  revolves, 
and  the  upper  part  may  be  rolled  off,  if  desired,  upon  a 
roller  placed  above  the  machine. 

When  a  skin  is  divided  throughout,  in  order  to  replace 
it  by  a  fresh  one,  it  is  necessary  to  lower  the  cylinder 
from  its  position,  in  order  to  disengage  the  knife  from 
the  surfaces.  For  this  purpose,  the  cushions  r  of  its 
axle  are  adjusted  in  movable  collars  supported  upon 
uprights  s  and  s',  which  can  be  elevated  or  lowered  by 
means  of  iron  swipes  which  are  supported  upon  the 
base  of  the  framework  e,  and  are  connected  by  a  cross- 
bar, or  treadle,  which  the  workman  can  lower  by  a  pres- 
sure of  his  foot,  the  collars  and  uprights  being  only  mov- 
able in  a  vertical  direction.  In  order  that  the  cog-wheel 
and  the  screw  may  continue  in  gear  during  this  change 
of  position,  the  cushions  wdiich  support  the  axle  of  the 
latter  are  connected  with  the  crossbar  between  the 
two  uprights. 

The  revolution  of  the  cylinder  can  be  stopped  at  plea- 
sure by  ungearing  the  wheel  E,  which  can  be  moved 
upon  its  axle  by  the  handle  u  and  fork  v. 


SPLITTING  AND  SHAYING  LEATHER. 


525 


Thirty-six  raw  hides  can  be  readily  divided  by  this 
machine  in  a  day  of  twelve  hours. 

Richardson's  Machine. — This  machine,  the  invention 
of  Alpha  Richardson,  of  Massachusetts,  is  that  generallj- 
used  throughout  the  United  States.  It  serves  for  split- 
ting either  green  or  tanned  hides.  There  are  two  modi- 
ficationS;  that  shown  in  perspective,  by  Fig.  190,  is 


Fig.  190. 


intended  for  splitting  upper  leather,  which  is  drawn  be- 
tween the  knife  and  roller,  by  means  of  a  crank  and  wind- 
lass. This  is  styled  the  Tanner  and  Curriers'  Machine. 
A  is  the  cast-iron  piece  connected  with  the  gauge-roller 
B,  which  revolves  on  the  centres  e  e,  and  is  turned  up  by 
the  lever  o  to  allow  the  placing  of  the  leather  upon  the 
top  of  the  knife  and  back-spring  A  A.  The  skin  being 
in  right  position,  the  gauge  is  then  turned  back,  and  forms 
the  gauge  for  the  thickness  of  the  skins  which  may  be 
regulated  at  will,  by  means  of  the  screws  h  h.  B  is  the 
roller  with  the  sectional  tubes  g  g  g,  which  are  arranged 
to  turn  on  its  end,  and  to  serve  as  friction-rollers  when 
the  shanks  and  loose  part  of  the  skin  are  being  drawn 
through.  The  knife  D  is  bolted,  firmly,  to  the  bed  by 
the  screws  Hi  i.    The  leather  is  placed  upon  the  cylin- 


526  SPLITTING  AND  SHAVING  LEATHER. 


der  Cy  and  drawn  through  against  the  knife  D  by  the  aid 
of  the  crank  at  the  end  of  the  machine. 

The  leather  is  prepared  for  splitting  by  being  only 
partially  dried.  In  New  England  and  in  the  middle 
States  it  is  generally  split  before  it  is  wholly  tanned,  as 
the  quality  of  the  leather  is  thought  to  be  improved  by 
finishing  the  tanning  after  it  has  been  thinned  or  divided 
by  the  machine. 

The  other  modification  of  the  machine  is  constructed 
for  splitting  and  skinning  sole  leather,  welt  leather,  and 
stifFenings  for  boot  and  shoemaker's  use.  It  is  repre- 
sented by  Fig.  191,  and  works  by  means  of  rollers  which 


force  the  leather  against  the  edge  of  the  knife.  A  is  the 
gauge-roller,  which  is  regulated  by  screws  according  to 
the  thickness  it  is  desired  to  split  the  skin.  B  is  the 
lower  roller,  which  forces  the  leather,  or  hide,  against 
the  knife,  and  the  two  are  put  in  motion  by  the  crank, 
&c.,  at  the  end.  The  leather  must  be  damped  through 
before  being  placed  in  the  machine. 

Seguin's  Shaving  and  Smoothing  Machine.  —  This 
machine  consists  of  two  metallic  rollers,  each  six  feet  six 
inches  long;  one  of  them  five  and  nine-tenth  inches  in  dia- 
meter, having  a  cutting-blade  set  spirally  into  its  surface, 
and  intended  to  pare  the  skin  wrapped  around  the  other 
roller,  which  is  two  feet  five  inches  in  diameter.  A  lon- 
gitudinal groove  in  the  surface  of  the  lower  roller  re- 


Fig.  19L 


SPLITTING  AND  SHAVING  LEATHER. 


527 


ceives  the  end  of  the  hide,  which  is  kept  in  place  by 
means  of  wedges.  The  cutting-blade  begins  to  form  a 
spiral  at  the  middle  of  the  upper  roller,  and  makes  the 
entire  circuit  on  both  sides  before  reaching  the  ends. 
The  pivots  of  the  lower  roller  turn  in  two  fixed  supports, 
and  those  of  the  upper  one  in  two  levers,  by  means  of 
which  it  can  be  lowered  upon,  or  raised  from  the  surface 
of  the  first  one.  These  rollers  turn  in  opposite  direc- 
tions, and  their  motion  is  so  adjusted  that  the  lower  one 
turns  completely  around  once,  while  the  upper  is  making 
twelve  revolutions. 

The  end  of  the  leather  having  been  engaged  in  the 
groove,  it  is  gradually  wound  upon  the  roller,  while  the 
levers  upon  which  the  upper  roller  turns  being  charged 
with  smaller  or  greater  weights,  as  the  case  requires,  the 
skin,  with  its  grain  side  up,  is  shaved  from  the  centre  to 
the  sides,  throughout  its  whole  extent.  Fig.  192  is  a 
front  view,  and  Fig.  193  a  side  view  of  this  machine. 


Fig.  192.  Fig.  193. 


H,  the  lower  roller,  with  the  horizontal  groove  a  for  the 
end  of  the  leather;  i,  upper  roller,  with  the  blade  Z), 
curving  spirally  from  the  centre;  K,  lever  carrying  the 
roller,  and  supported  by  the  crosspiece  l. 


NOSSITER  S  PROCESSES. 


These  improvements,  patented,  in  England,  October 
10,  1845,  are:— 


528  SPLITTING  AND  SHAYING  LEATHER. 


1.  For  a  mode  of  shaving  tanned  or  dressed  hides  and 
skinSj  by  applying  knives  set  tangentially  to  a  rotatory 
axis,  in  pLice  of  performing  such  operation  by  hand. 

2.  A  mode  of  causing  the  grease,  or  oil  of  sheep,  lamb, 
and  other  skins,  requiring  such  process,  to  be  expressed 
out  by  means  of  rollers. 

3.  A  mode  of  unhairing,  fleshing,  and  removing  grease 
and  filth  from  hides  and  skins,  by  the  employment  of  a 
rotatory  axis  with  knives  or  blades. 

Fig.  194  "  shows  a  section  of  so  much  of  a  machine  as 
will  enable  me  to  describe  this  part  of  my  invention :  a 
is  a  roller,  on  which  is  fixed  a  series  of  knives,  fixed 
tangentially;  and  although  they  will  act  very  well  when 
in  a  line  with  the  axis,  yet  I  prefer  them  to  incline  across 
the  axis  to  a  small  extent,  so  that  each  blade  may  come 
into  action  progressively,  and  not  all  parts  at  the  same 
moment;  c  is  a  bed,  or  surface,  covered  with  copper,  to 
prevent  the  iron  staining  the  leather ;  or  other  suitable 


Fig.  194.  Fig.  195. 


m — 9- 


bed  may  be  used :  d  cZ,  are  two  rollers,  which  draw  for- 
ward the  skins,  or  hides,  so  that  the  skins,  or  hides,  may 
be  held  tightly  over  the  bed,  c,  and,  in  introducing  the 
hides,  or  skins,  the  revolving  cutter  is  raised  off  the  bed. 
The  speed  at  which  the  parts  move  are  written  thereon, 
but  the  same  may  be  varied.  By  this  arrangement  of 
machinery,  the  knives  w^ill  shave  or  cut  the  hides  and 


SPLITTING  AND  SHAVING  LEATHER. 


529 


skins  submitted  to  its  operation,  so  as  to  reduce  the 
thickness  to  the  degree  desired,  and  this  in  a  more  uni- 
form manner  than  when  performing  the  same  process  by 
hand-Labor,  with  suitable  knives,  as  heretofore  generally 
practised." 

The  second  part  of  the  invention  is  illustrated  by  Fig. 
195:  "/^  are  two  smooth  rollers,  between  which  the 
skins  are  passed ;  the  surface  of  the  upper  roller  being 
pressed  closely  down,  so  as  to  offer  a  sufficient  pressure 
to  remove  the  grease  and  oil  from  the  skins  when  in  the 
'  pelt'  state ;  and  this  means  of  performing  this  process 
will  be  found  more  useful  than  the  means  of  pressure 
now  resorted  to." 

The  third  part  of  the  invention  is  shown  in  Fig.  196  : 
It  is  a  roller,  having  a  series  of  blades  of  steel,  or  other 
suitable  material,  set  radially  from  the  axis;  each  blade 
should  be  as  long  as  the  roller  on  which  it  is  fixed,  so 
that  each  blade  may  be  as  wide  as  the  skin  submitted  to 
its  action.    This  mode  of  working  is  to  be  substituted 


for  the  hand-working  with  knives  now  resorted  to  for 
unhairing  and  fleshing,  and  also  paring  or  graining  hides 
and  skins ;  and  I  use  a  cylindrical  rotatory  brush  (Fig. 
197),  for  removing  the  surface-grease  and  filth  from  the 
hides  and  skins." 


Fig.  196. 


Fig.  197. 


1  Revolution. 


CHAPTER  LIV. 


EMBOSSING  OF  LEATHER. 

This  is  a  method  of  manufacturing  ornamental 
leather  intended  for  furniture,  hangings,  bookbinding, 
and  other  uses. 

BERNHEIM  AND  LABOURIAu'S  PROCESS. 

The  plates,  by  means  of  which  the  figures  in  relief 
are  stamped  upon  the  leather,  in  this  process,  are  made 
of  type-metal,  or  fusible  alloy,  cast  in  plaster  moulds, 
on  which  the  reverse  of  the  figures  has  been  designed. 
The  type-metal  plates  are  used  for  stamping  leather 
without  the  assistance  of  a  press,  by  which  they  would 
be  broken  to  pieces,  and  those  of  fusible  alloy  are  em- 
ployed for  large  single  designs  in  panel  upon  hangings, 
or  for  the  repetition  of  the  same  figures,  by  associating 
a  number  of  plates  together.  For  this  latter  purpose, 
as  many  plates  as  are  necessary  for  the  whole  design  are 
placed  together  upon  a  level  surface,  in  their  proper 
places,  and  their  edges  are  then  joined  together,  first  by 
running  a  hot  iron  along  them,  and  then  by  filling  up 
the  interstices  with  melted  fusible  metal.  The  project- 
ing veins  of  metal  are  then  cut  and  scraped  ofi*,  and  the 
whole  presents  the  appearance  of  a  single  plate. 


EMBOSSING  OF  LEATHER. 


531 


The  large  plates  thus  prepared,  will  not  bear  the  force 
of  a  press,  but  are  used  with  the  assistance  of  heat.  The 
ingredients  of  which-  the  alloy  is  composed,  are  not  in 
the  proportion  to  make  the  most  fusible  metal,  the  quan- 
tity of  lead  being  somewhat  greater  than  in  the  ordinary 
alloy.  Those  plates  which  are  intended  to  be  subjected 
to  the  action  of  the  press,  also,  have  a  smaller  quantity 
of  tin  in  their  composition  than  is  usual,  so  as  not  to  be 
rendered  brittle  by  an  excess  of  it.  These  latter  should 
be  perfectly  smooth  below,  and  should  be  of  considerable 
thickness.  They  are  prepared  of  the  proper  thickness 
in  the  following  manner :  A  fine  thin  sheet  of  tin-foil  is 
first  pressed  into  all  the  cavities  of  the  original  plaster 
mould,  so  as  to  give  a  reversed  copy  of  it,  and  a  plate  of 
softened  wax  of  the  desired  thickness  of  the  metal  plate, 
is  forced  into  it  so  as  to  take  its  form.  A  plaster  mould 
is  then  taken  of  this  wax  impression,  covered  with  tin- 
foil, and  the  model  and  the  mould,  placed  parallel  to  each 
other,  are  separated  by  little  leaden  tubes,  which  are  equal 
in  height  to  the  thickness  of  the  wax-plate  before  used. 

In  order  that  the  casting  should  be  successful,  the 
plaster  models  and  moulds  must  be  perfectly  dry,  and 
heated  to  the  temperature  of  the  fused  alloy,  and  when 
filled  must  be  placed  in  a  position  to  cool  rapidly. 

The  large  compound  plates  are  exposed,  in  stamping, 
to  the  action  of  heat  by  means  of  pipes  conveying  steam, 
placed  below  them. 

Two  means  of  stamping  leather  with  figures  in  relief 
are  resorted  to,  that  by  the  use  of  the  press,  and  that  in 
which  the  stamping  is  effected  by  hand  or  the  chisel, 
with  the  assistance  of  heat.  The  leather  is  first  fulled 
in  tepid  water,  until  it  becomes  as  soft  as  it  is  possi- 
ble to  make  it.  In  this  condition  it  is  placed  upon 
the  plate  without  being  stretched,  and  is  made  to  enter 


532 


EMBOSSING  OF  LEATHER. 


all  the  depressions  of  the  figures  by  pressing  and  squeez- 
ing it  in  every  direction  with  the  fingers,  while  the  pro- 
jections and  folds  upon  the  edges  of  the  design,  are 
smoothed  down  by  a  wooden  instrument  like  the  chisel 
used  by  sculptors.  When  the  leather  is  in  contact  with 
all  parts  of  the  mould  or  plate,  if  the  character  of  the 
figures  is  such  as  to  admit  of  perpendicular  pressure,  the 
frame  is  filled  up  with  warm  sawdust,  and  the  gentle 
force  of  a  press  is  applied  above,  so  as  to  keep  the  leather 
and  metal  surfaces  in  contact.  After  a  time,  the  screw 
is  loosened,  the  moistened  sawdust  is  removed,  and  re- 
placed with  fresh,  the  press  is  again  brought  to  bear,  and 
this  process  is  repeated  once  more.  At  the  end  of  the 
third  operation,  the  leather  will  generally  have  acquired 
enough  consistency  to  retain  the  form  impressed  upon  it, 
and  it  may  then  be  removed  from  the  plate  and  dried  in 
the  stove-room. 

If  the  plate  be  too  large  for  the  press,  or  if  there  are 
many  projections  on  its  surface,  having  slight  or  nar- 
row bases,  the  pressure  must  be  conducted  entirely  by 
hand.  For  this  purpose  the  plate  is  warmed  by  placing 
it  upon  the  tubes  conveying  hot  air  or  steam,  and  the 
moistened  leather  is  laid  upon  it,  and  forced  down  into 
all  the  depressions  and  grooves  of  the  plate  by  means  of 
paper-hangers'  paste,  which  is  thrust  and  pressed  down 
into  them  with  the  end  of  the  wooden  instrument  or 
chisel,  and  when  the  chief  cavities  are  filled  in  this  way, 
the  rest  of  the  surface  is  worked  so  as  to  bring  the 
leather  in  contact  with  the  plate  in  every  part.  The 
folds  which  form  at  the  borders  and  corners,  are  then 
smoothed  out  with  the  chisel,  first  longitudinally,  and 
then  across,  until  they  are  made  to  disappear.  The  whole 
surface  of  the  leather  is  then  rubbed  with  a  dry  sponge 
so  as  to  remove  the  excess  of  moisture,  and  the  workman 


V 

EMBOSSING  OF  LEATHER. 


533 


then  continues  forcing  it  clown  into  the  depressions  with 
a  chisel,  until  it  is  perfectly  dry,  w^hen  the  rest  of  the 
paste  is  removed  from  the  hollows.  The  elasticity  of  the 
leather,  when  dry,  allows  of  its  removal  from  the  plates 
even  when  the  elevations  on  the  latter  are  larger  at  top 
than  at  bottom. 

If  it  is  intended  to  stamp  a  design,  or  series  of  designs, 
the  dimensions  of  which  require  the  use  of  a  number  of 
skins,  the  latter  are  first  cut  into  parallelograms,  and  their 
edges  are  pared  and  thinned  down.  One  of  them  in  the 
softened  state  is  then  placed  at  an  angle  or  edge  of  the 
plate,  and  is  impressed  with  the  figures  in  the  manner 
before  described.  A  second  skin  is  then  placed  alongside 
of  the  first,  with  one  edge  projecting  about  an  inch  over 
its  border,  and  is  printed  in  the  same  way ;  a  third  is 
placed  next  to  and  partly  over  the  second,  and  so  on, 
even  if  a  number  of  rows  of  skins  are  required,  until  the 
whole  extent  of  the  plate  is  occupied.  After  the  skins 
have  all  been  pressed,  sponged,  worked  with  the  chisel, 
and  dried,  their  overlying  edges  are  gently  raised,  cov- 
ered with  strong  glue,  carefully  replaced,  and  retained  in 
their  original  position,  by  covering  the  whole  with  saw- 
dust and  weighted  planks,  until  it  dries  and  forms  a 
continuous  sheet. 

By  these  two  processes,  leather  beautifully  ornamented 
in  relief,  and  suitable  for  many  purposes  of  luxury,  ma}^ 
be  manufactured.  These  ornaments  may  be  allowed  to 
retain,  in  a  slight  degree,  the  suppleness  and  elasticity  of 
the  leather,  or  may  be  rendered  perfectly  firm  and  hard, 
by  pouring  into  them,  v/hile  still  warm  upon  the  castings, 
a  solution  of  gum-lac  in  alcohol,  or  a  watery  solution  of 
glue,  and  filling  up  all  the  depressions  with  paste,  saw- 
dust, or,  what  is  still  better,  the  raspings  of  cork  mixed 
with  glue.    Their  surfaces  may  be  made  impervious  to 


534 


EMBOSSING  OF  LEATHER. 


moisture,  by  the  penetration  of  the  gum-lac  or  of  other 
resinous  material,  and  may  be  painted,  gilded,  and  var- 
nished. 

F.  w.  east's  process. 

This  invention,  patented  in  1851,  differs  from  the 
usual  method  in  being  exclusively  applicable  to  the  flesh 
side  of  leather,  and  thus  producing  an  effect  superior  to 
that  obtained  by  embossing  the  grain  side.  It  is  adapted 
to  all  tanned  skins  except  those  which  are  oil-tanned. 

The  skins,  just  sufficiently  shaved  to  remove  flaws  and 
give  them  uniform  thickness,  are  to  be  immersed  in  water 
of  120°  F.,  and  brushed  on  the  flesh  side  to  remove  dirt 
and  open  the  fibre.  They  are  then  to  be  folded  grain- 
side  inwards  and  the  edges  sewed  together  in  bag  form, 
so  as  to  prevent  the  intrusion  of  the  dye.  The  dyeing 
succeeds  '^scouring,"  and  sweetening,"  and  is  effected 
with  much  weaker  liquors  than  are  used  for  dyeing  the 
grain  side  of  skins;  but  requires  a  longer  time,  as  the 
process  must  be  several  times  repeated  in  order  that  the 
color  may  penetrate  the  fibres,  and  appear  uniform.  They 
are  then  rinsed,  opened,  and  dried. 

When  dry,  they  are  to  be  "perched"  on  the  flesh  side 
with  a  moderately  sharp  knife,  so  as  to  soften  the  fibres, 
and  nap  the  surface  without  cutting  the  flesh  off.  Each 
skin  is  to  be  again  folded  as  before,  and  passed  through 
a  glutinous  solution  of  one  part,  by  measure,  of  size  in 
three  parts  of  water;  then  stretched  on  boards  to  dry, 
trimmed  around  the  edges,  and  bruised  on  the  surfaces 
with  cork,  to  render  them  soft,  the  flesh  side  being  kept 
outwards. 

The  skins,  just  previous  to  being  embossed,  are  moist- 
ened on  the  grain  sides  with  clean  water,  and  then  laid 


EMBOSSING  OF  LEATHER. 


535 


together^  with  the  grain  sides  in  contact,  and  under  cover 
in  order  to  prevent  access  of  air,  and  thus  to  promote  the 
thorough  penetration  of  the  water  through  the  hide, 
thereby  making  the  gelatinous  matter  auxiliary  to  the 
production  of  a  gloss  upon  the  embossed  parts.  The 
embossing  is  done  with  engraved  rollers,  previously 
heated  to  250°,  and  exactly  in  the  same  manner  as  is 
employed  for  embossing  velvet,  cloth,  &c. 


CHAPTER  LV. 


GUT-DEESSING. 

The  art  of  the  gut-dresser  consists  in  separating  the 
middle  or  muscular  coat  of  the  intestines  of  certain 
animals  from  its  external  or  peritoneal  covering,  and 
from  its  internal  lining  or  mucous  membrane,  and  may 
be  divided  into  two  distinct  branches;  the  preparation 
of  the  intestines  of  oxen  and  cows,  for  the  preservation 
of  alimentary  substances,  and  that  of  the  intestines  of 
sheep,  for  the  manufacture  of  cords  for  various  purposes. 
These  subjects  will  be  treated  of  under  their  appropriate 
headings. 

PREPARATION  OF  THE  INTESTINES  OF  CATTLE. 

The  workshop  of  the  gut-dresser  generally  consists  of 
a  room  about  20  feet  long,  16  feet  wide,  and  12  feet  high, 
with  four  windows  which  are  kept  closed  in  winter,  and 
are  opened  in  summer.  Casks  or  tubs,  each  capable  of 
containing  about  60  gallons,  are  ranged  around  its  sides; 
and  wooden  stakes  are  fixed  in  the  ground  in  the  middle 
of  the  room,  for  attaching  hooks.  The  feculent  matters, 
and  the  remnants  from  the  intestines,  are  usually  allowed 
to  lie  about  the  floor,  and  exhale  an  odor,  which,  with 
that  from  the  putrefying  intestines  in  the  tubs,  is  the 
most  disgusting  that  can  be  conceived,  and  is  so  perm  a- 


GUT-DEESSING. 


537 


nent,  that  the  bodies  as  well  as  the  clothes  of  the  work- 
men remain  for  a  long  time  impregnated  with  it. 

A  well  is  usually  sunk  in  a  yard  attached  to  the  build- 
ing, for  receiving  the  excrementitious  and  waste  matters 
of  the  manufactory. 

The  intestines  are  subjected  to  various  operations, 
which  will  be  described  in  order. 

The  small  intestines  of  oxen  and  cows,  as  soon  as  they 
are  brought  to  the  workshop  from  the  slaughter-house, 
are  steeped  in  water  contained  in  the  casks,  in  order  to 
moisten  and  smooth  the  surfaces,  so  that  the  knife  may 
glide  easily  over  them.  When  this  is  accomplished,  an 
end  of  one  of  the  intestines  is  attached,  by  tying  it  in  a 
kind  of  knot  around  a  hook,  to  one  of  the  stakes  in  the 
centre  of  the  room,  at  a  height  of  six  or  seven  feet  above 
the  floor.  The  workman,  then  grasping  the  depending 
portion  between  the  thumb  and  first  finger  of  the  left 
hand,  and  gradually  sliding  the  hand  down  along  the 
whole  length  of  the  intestine,  follows  its  motion  by  pass- 
ing a  knife  held  in  the  right  hand,  over  the  surface,  so 
as  to  separate  the  fat,  and  as  much  as  possible  of  the 
outer  or  peritoneal  coat.  Another  portion  of  gut  is  then 
treated  in  the  same  way,  and  the  operation  is  continued 
until  all  the  contents  of  the  casks  have  been  cleaned. 

If  any  parts  of  the  intestine  have  been  scratched  or 
divided  by  the  butchers  in  separating  the  fat,  these  are 
cut  ofi"  and  thrown  aside.  The  fat  falling  to  the  ground' 
is  separated  from  the  feculent  and  other  matters,  and 
after  being  washed  a  number  of  times,  is  dried,  melted, 
and  rendered. 

The  intestines  are  next  washed  in  a  large  cask  half 
full  of  pure  water,  and  the  workman  then  proceeds  to 
turn  them  inside  out,  by  introducing  a  thumb  into  the 
interior  of  each,  and  working  the  gut  upon  it  with  the 

35 


538 


GUT-DRESSING. 


fingers  until  the  whole  is  inverted.  A  number  of  the 
pieces  are  then  tied  together  at  their  ends  with  a  cord 
which  is  attached  to  the  edge  of  the  cask,  and  when  a 
sufficient  number  of  inverted  intestines  are  thus  fastened, 
they  are  left  with  only  their  original  contents  of  water, 
to  undergo  the  next  process,  that  of  putrefaction. 

The  experience  of  the  workman  alone  can  guide  him  in 
determining  when  putrefaction  is  sufficiently  established. 
It  should  be  carried  only  far  enough  to  disorganize  the 
mucous  membrane  and  other  parts  which  are  to  be  sepa- 
rated from  the  middle  coat  of  the  intestines;  and  if  al- 
lowed to  advance  too  far,  the  whole  tissue  will  be  soft- 
ened and  rendered  useless. 

Two  or  three  days'  exposure  in  summer,  and  from  five 
to  eight  in  winter  are  usually  sufficient,  and  putrefaction 
is  known  to  have  reached  the  proper  stage,  when  bubbles 
of  gas  begin  to  escape  from  the  surface  of  the  intestines. 
This  operation  is  the  most  disgusting  one  to  which  the 
workmen  are  exposed,  from  the  fetid  effluvia  generated 
by  the  decomposing  animal  matters;  but  it  does  not  seem 
to  be  as  injurious  to  the  health  of  those  working  in  the 
room  as  might  be  supposed. 

When  sufficiently  rotted,  the  pieces  are  untied,  soaked 
in  a  cask  half  full  of  fresh  water,  and  the  next  operation 
consists  in  separating  the  disorganized  mucous  lining, 
which  is  now  upon  the  outside.  This  the  workman  pro- 
ceeds to  effect  by  scraping  it  off  with  his  thumb-nails, 
until  it  is  entirely  detached.  The  operation  is  facilitated 
by  dipping  the  pieces  frequently  in  water.  The  intes- 
tines are  then  repeatedly  soaked  and  washed  in  clean 
water  until  it  comes  from  them  unclouded  and  free  from 
taint. 

When  perfectly  clean,  one  end  of  each  piece  of  intes- 
tine is  tied  with  a  string,  and  the  workman  introduces 


GUT-DRESSING. 


539 


into  the  other  orifice  a  hollow  cylinder  of  cane  angle  or 
reed  about  five  inches  long,  and  after  making  the  joint 
air-tight  by  pressing  the  rim  of  the  gut  tightly  around 'it, 
applies  his  mouth  to  the  end,  and  expands  the  gut  by 
blowing  into  it,  and  then  closes  the  orifice,  tying  it 
tightly  with  a  cord.  If  holes  are  found,  the  intestine  is 
cut  otF  at  the  place  where  they  occur,  and  tied  again  with 
a  cord.  When  all  the  pieces  are  thus  filled  with  air, 
they  are  carried  in  baskets  to  the  drying  place,  and  are 
laid  out  so  as  not  to  be  in  contact  with  each  other,  upon 
horizontal  poles  placed  about  five  feet  from  the  ground. 

When  perfectly  dry,  the  pieces  of  gut  are  taken  down, 
and  cut  across  with  scissors  as  near  the  ligatures  as  pos- 
sible, after  which  they  are  pressed  and  flattened  with 
the  hand,  so  as  to  expel  all  the  air  contained  in  them. 

They  are  then  assorted  into  different  sizes  according 
to  the  purposes  for  which  they  are  intended,  are  col- 
lected in  bundles,  and  hung  in  a  damp  place,  preparatory 
to  being  subjected  to  the  action  of  sulphurous  fumes. 

After  being  kept  in  a  damp  situation  for  some  time, 
the  intestines  are  exposed  to  the  vapor  of  sulphur  in 
a  stove  or  chamber,  five  and  one-third  feet  square,  and 
six  and  a  half  feet  high.  For  this  purpose,  they  are 
strung  on  sticks,  and  if  not  sufficiently  moist  when  intro- 
duced into  it,  they  are  sprinkled  over  with  water  from  a 
brush,  and  are  then  suspended  across  the  upper  part  of 
the  chamber  to  the  number  of  a  hundred  bundles.  A 
pound  or  more  of  flowers  of  sulphur  is  then  put  in  an 
earthen  dish  in  the  bottom  of  the  chamber,  and  ignited 
by  burning  coals  thrown  upon  it;  the  door  of  the  cham- 
ber being  immediately  closed,  and  the  further  precaution 
to  prevent  the  escape  of  vapors  being  taken  of  luting  it 
around  the  edges,  and  of  gluing  stout  pieces  of  paper 
upon  any  apertures  which  exist  in  the  stove. 


540 


GUT-DEESSING. 


At  the  expiration  of  some  hours^  the  door  is  opened 
and  the  vapors  are  allowed  to  escape.  The  intestines, 
by*being  thus  exposed  to  the  action  of  sulphurous  acid, 
are  bleached,  deprived  of  their  unpleasant  odor,  and 
are  protected  against  the  attacks  of  insects.  While 
still  damp,  they  are  twisted  into  hanks,  packed  with 
camphor,  and  sent  to  market. 

DISINFECTION  OF  THE  WORKSHOP,  AND  MODE  OF  SUPPRESSING 

PUTREFACTION. 

In  order  to  prevent  the  offensive  effluvia  arising  from 
the  putrefaction  of  intestines,  the  following  process  of 
separating  the  mucous  membrane  has  been  devised  by 
Labarraque,  who  received,  as  a  reward  for  it,  the  pre- 
mium of  the  French  Society  for  the  Encouragement  of 
National  Industry. 

The  small  intestines  of  fifty  cattle,  which  have  been 
cleaned  and  turned  inside  out,  are  mixed  in  a  cask  with 
two  buckets-full  of  water  containing  three  and  a  half 
pounds  of  chlorinated  liquor  of  potassa,  at  12°  or  13° ;  and 
if  there  be  not  then  enough  liquid  to  cover  them,  another 
bucket-full  of  fresh  water  is  added.  The  whole  is  then 
stirred  about,  well  mixed,  and  left  over  night.  The 
membrane  can  be  detached  as  easily  the  next  day,  as  after 
many  days  of  putrefaction  in  the  ordinary  method,  and 
the  noxious  and  unpleasant  odor  is  entirely  avoided. 
The  succeeding  operations  are  performed  in  the  usual 
manner. 

goldbeater's-skin. 

Goldbeater's-skin  is  prepared  from  the  external  or 
peritoneal  coat  of  the  coecum,  or  bhnd  gut  of  neat 


GUT-DRESSING. 


541 


cattle.  The  workman  separates  and  turns  over  the 
portion  which  encircles  the  junction  of  this  pouch  with 
the  rest  of  the  intestines,  and  draws  it  off  inverted,  from 
the  other  coats,  to  the  length  of  twenty-five  or  thirty 
inches.  It  is  then  immersed  for  a  short  time  in  a  weak 
solution  of  potash,  and  is  cleaned  by  scraping  upon  a 
board  with  a  knife.  When  well  cleaned  in  this  way, 
and  by  soaking  in  water,  the  piece  is  stretched  upon  a 
kind  of  frame  from  forty  to  fifty  inches  in  length,  and 
eleven  inches  in  width,  and  made  of  two  uprights  held 
together  by  two  crosspieces,  having  longitudinal  grooves 
two  and  half  lines  in  width.  The  surface  of  the  mem- 
brane which  was  outside  in  the  animal,  is  placed  in  con- 
tact with  the  upper  part  of  the  frame,  and  one  end  being 
placed  upon  the  top  of  the  frame,  it  is  stretched  in  every 
direction,  and  is  glued  to  its  rim.  Another  membrane 
is  then  stretched  above  the  first,  with  its  external  sur- 
face placed  upwards,  and  is  attached  to  it  by  gluing 
around  the  edges.  When  perfectly  dry,  the  membranes 
are  separated  by  running  a  sharp  knife  along  the  grooves. 
Each  strip  is  then  glued  upon  a  frame  similar  to  the  first 
one,  but  without  a  groove,  and  is  washed  over  with  a  solu- 
tion composed  of  an  ounce  of  alum  dissolved  in  four  pints 
of  pure  water.  When  the  surface  is  dry,  a  sponge  dipped 
in  a  concentrated  solution  of  fish-glue  in  white  wine,  with 
enough  cloves,  nutmegs,  or  camphor,  to  make  it  aromatic, 
is  passed  over  it.  When  this  coating  is  dry,  it  is  covered 
with  a  coat  of  white  of  eggs,  and  the  strip  is  cut  into 
pieces  five  and  a  half  inches  square,  which  are  then 
smoothed  out  under  a  press,  and  made  up  into  leaves  for 
the  purpose  of  the  goldbeater. 


542 


GUT-DRESSING. 


LATHE-CORDS. 

These  cords  are  made  of  the  intestines  of  horses, 
cleaned  and  prepared  by  the  separation  of  the  mucous 
membrane,  in  the  manner  before  described.  A  wooden 
ballj  armed  in  its  lower  part  with  four  cutting  blades, 
at  equal  distances  from  each  other,  is  fixed  by  an  up- 
right piece  of  wood  to  a  bench.  The  end  of  an  intestine 
is  then  drawn  over  this  ball,  and  as  the  gut  is  pulled 
downwards,  it  is  divided  into  four  equal  bands  or  strips. 

Four  or  eight  of  these  strips,  according  to  the  thick- 
ness which  it  is  intended  to  give  to  the  cord,  are  tied 
with  a  peculiar  knot  to  one  end  of  a  thick  piece  of  cord. 
The  end  is  passed  around  a  peg  introduced  into  a  hole 
in  a  solid  post,  to  the  side  of  which  a  number  of  pegs 
are  attached.  At  a  distance  of  ten  or  eleven  yards  from 
the  first  one,  another  post  is  fixed,  similarly  provided  with 
pegs,  and  over  one  of  these  latter,  the  middle  of  the  assem- 
blage of  strips  is  passed,  the  other  end  being  brought 
back  and  attached  to  the  first  peg,  by  means  of  another 
knotted  cord.  The  tied  ends  of  the  strips  are  then 
attached  to  the  wheel  by  a  hook  connected  with  the 
loJiirl,  which  is  made  to  revolve  until  the  strips  are  suf- 
ficiently twisted.  The  twisted  end  is  then  kept  stretched 
by  attaching  it  to  the  peg,  and  any  projecting  filaments 
are  cut  ofil  After  being  stretched  for  some  time,  the  cords 
are  then  twisted  again,  and  a  third  and  a  fourth  time 
are  twisted  by  hand,  being  each  time  rubbed  with  and 
drawn  through  a  bunch  of  moistened  horse-hair  after  the 
twisting,  and  again  stretched  out  between  the  two  posts. 
If  the  cord  is  not  smooth  and  even  after  the  twisting  is 
completed,  it  is  made  so  by  rubbing  with  a  piece  of  dog- 
skin.   It  is  then  dried,  and,  by  some  manufacturers,  is 


GUT-DRESSING. 


543 


exposed  to  the  vapors  of  sulphur.  Finally,  the  ends  are 
cut  off,  and  the  cord  is  rolled  in  a  coil. 

In  order  to  avoid  the  emanations  from  the  putrefying 
intestines,  which  are  generally  brought  to  the  workshop 
in  a  state  of  incipient  decomposition,  Labarraque  recom- 
mends that  they  be  at  once  cleaned,  turned  inside  out, 
and  put  to  soak  over  night  in  a  cask,  containing,  for  fif- 
teen or  twenty  intestines,  one  pound  one  and  a  half 
ounces  of  chlorinated  potash  liquor  at  from  13°  to  18°, 
mixed  with  two  buckets-full  of  pure  water.  The  mucous 
membrane  is  ready  to  be  detached  the  next  day,  and 
after  its  removal  and  thorough  washing,  the  intestines 
can  at  once  be  prepared,  as  has  been  already  described. 

MANUFACTURE  OF  CORDS,  IMPROPERLY  CALLED  CAT-GUT,  FROM 
THE  INTESTINES  OF  SHEEP. 

The  intestines  are  removed  from  the  body  of  the  ani- 
mal when  warm,  are  cleaned  and  freed  from  fecal  matter, 
and  are  at  once  sent  to  the  workshop.  If  not  perfectly 
clean  at  first,  and  if  decomposition  has  been  allowed  to 
commence,  they  are  indelibly  stained,  so  as  to  be  unfit 
for  most  of  the  purposes  for  which  they  are  intended. 

After  being  unravelled  and  deprived  of  adhering  fat, 
while  soaking  in  a  tub  of  water,  they  are  placed  in  fresh 
water,  and  the  small  ends  of  all  the  intestines  are  tied 
together,  and  laid  on  the  edge  of  the  tub,  while  their 
bodies  are  left  to  steep  for  two  or  three  days  in  water, 
which  is  frequently  changed,  particularly  in  summer. 
By  this  means,  the  removal  of  the  mucous  and  perito- 
neal coats  is  facilitated.  After  this,  the  bunch  of  intes- 
tines is  placed  upon  a  bench  which  slopes  down  towards 
the  edge  of  the  tub,  and  the  surface  is  scraped  with  the 
back  of  a  knife-blade,  in  order  to  separate  and  remove 


544 


GUT-DRESSING. 


the  external  membrane  in  breadth  of  about  half  the  cir- 
cumference. This  coat,  which  is  called  filandre  by  the 
French  manuflicturers,  can  only  be  freely  removed  in 
pieces  of  the  proper  size  and  length  by  pulling  it  off  in 
the  direction  from  the  small  to  the  large  end  of  the  in- 
testine. It  is  employed  as  thread  to  sew  intestines,  and 
to  make  the  cords  of  rackets  and  battledores.  In  the 
event  of  its  breaking,  the  separated  pieces  must  be  tied 
together,  and  they  and  the  others  are  laid  aside  for  use. 

The  guts  are  then  soaked  in  fresh  water  for  twenty- 
four  hours  more,  and  are  taken  out  and  scraped  clean 
upon  the  bench  with  the  back  of  a  round-bladed  knife. 
About  eight  feet  of  the  larger  ends  are  now  cut  off  and 
sold  to  the  sausage-makers.  The  rest  are  then  cut  of  a 
proper  length,  and  are  imbedded,  as  it  were,  between 
layers  of  salt.  Alternating  heaps  of  intestines  and  lay- 
ers of  salt  are  packed  in  until  all  the  intestines  have 
been  ^Ited.  After  some  days,  they  are  removed  and 
packed  with  a  small  quantity  of  salt,  so  as  to  be  ready 
fit  any  time  for  the  succeeding  processes. 

After  this  curing  is  completed,  the  intestines  are  taken 
out  and  soaked  over  night  in  fresh  water,  and  the  follow- 
ing day  are  deposited  in  a  lye  made  by  adding  four 
ounces  of  potash  and  the  same  quantity  of  pearlash,  to 
a  pail  of  water,  containing  about  three  or  four  gallons. 
The  exact  strength  of  the  lye  is  determined  by  the  ex- 
perience of  the  workmen,  and  the  effect  which  it  has 
upon  their  hands.  The  lye  is  poured  in  successive 
quantities  upon  the  intestines,  and  is  poured  ofl'  again 
every  two  or  three  hours,  until  they  have  been  sufficiently 
acted  upon.  They  are  then  drawn  two  or  three  times 
through  an  open  brass  thimble,  and  pressed  against  it 
with  the  nail,  in  order  to  scrape  off  unnecessary  and  pro- 


GUT-DRESSING. 


545 


jecting  parts  from  the  surfaces,  after  which  they  are  se- 
lected for  different  purposes,  according  to  their  sizes. 

Cord  for  Rachets. — This  is  generally  made  of  intes- 
tines of  inferior  quality  or  which  have  been  stained  by 
commencing  putrefaction.  The  pieces  while  still  moist, 
are  sewed  together  Avith  strips  of  the  outer  membrane  or 
filandre,  each  junction  being  cut  aslant,  so  as  to  make  it 
smooth  and  strong.  Three  or  four  of  these  intestines  are 
then  attached  by  strings  to  the  whirl,  and  are  twisted 
in  the  usual  way,  after  w4iich  the  cord  is  smoothed  and 
deprived  of  moisture  by  the  hand  of  the  workman,  and 
is  left  stretched  for  a  time.  It  is  again  twisted,  and 
rubbed  with  a  bunch  of  horse-hair.  The  inferior  kinds 
of  cords  are  made  by  twisting  one  gut  along  with  two  or 
three  pieces  of  the  filandre. 

Whip-cord  is  made  of  intestines  of  good  quality,  pre- 
pared, cut  slanting,  and  sewed  as  above  described.  Each 
end  is  then  twisted  separately,  as  whip-cord  is  seldom 
made  of  two  intestines  twisted  together.  The  cord  is 
sulphured  once  or  twice,  and  may  then  be  dyed  black 
with  common  ink,  or  of  a  rose-color  with  red  ink,  which 
the  sulphurous  acid  turns  to  a  pink  color,  or  with  a  green 
dye  sold  for  the  purpose  by  the  color  dealers.  The  cord 
is  then  dried,  smoothed,  and  coiled  up  into  suitable  sizes 
for  sale. 

Hatters  Cords  for  Boiostrings. — These  cords  are  usu- 
ally from  sixteen  to  twenty-eight  feet  long,  and  are  made 
by  twisting  the  longest  and  largest  intestines  of  sheep, 
four,  six,  eight,  ten,  or  twelve  being  put  together,  accord- 
ing to  their  intended  size.  The  preparation  of  this  kind 
of  cord  demands  more  care  than  that  of  those  which  have 
already  been  described,  and  it  must  be  perfectly  free 
from  seams  and  knots.  It  is  twisted  with  the  wheel  in 
the  ordinary  manner,  and  must  be  well  stretched  and 


546 


GUT-DRESSING. 


smoothed  after  each  operation.  When  half  dry,  it  is 
exposed  at  two  different  times  to  the  fames  of  burning 
sulphur,  after  which  it  is  well  rubbed  with  a  bunch  of 
horse-hair  rope  dipped  in  potash  lye,  and  is  finally  dried 
in  a  state  of  tension,  cut  off,  and  coiled. 

Cloch-malcers  Cord. — This  kind  of  cord  differs  from 
the  others  in  being  extremely  thin,  and  is  made  of  intes- 
tines of  the  smallest  size,  or  of  strips  made  by  dividing 
each  gut  into  two  pieces  by  drawing  it  down  over  a  kind 
of  lancet  mounted  upon  a  leaden  or  wooden  ball,  which 
guides  the  blade,  the  two  sections  of  the  gut  falling  into 
a  vessel  placed  beneath.  Clock-makers,  however,  some- 
times employ  cords  of  larger  diameter,  made  of  two  or 
more  intestines. 

Coi'ds  for  Musical-instrument  Strings. — The  strings  of 
musical  instruments  should  be  of  uniform  diameter, 
perfectly  smooth,  round,  and  free  from  shreds  or  fila- 
ments. They  should  be  as  little  liable  as  possible  to 
stretch  or  break,  and  should  preserve  their  polish  and 
transparency^  during  all  changes  of  weather.  Their 
manufacture  requires  great  experience  and  dexterity  on 
the  part  of  the  wwkmen.  The  best  violin  and  harp 
strings  have  been  made  from  time  immemorial  in  Italy, 
and  although  those  of  a  superior  quality  are  manufac- 
tured in  France,  the  preparation  of  treble  strings,  which 
are  peculiarly  difficult  to  make,  is  confined  to  Naples. 
The  membranes  of  lean  animals  are  well  known  to  be 
much  more  tough  than  those  of  animals  in  high  condi- 
tion, and  the  superior  quality  of  the  strings  made  at 
Naples  is  attributed  in  a  measure  to  the  smallness  and 
leanness  of  the  sheep  in  its  vicinit3^ 

The  guts  intended  for  fiddle  and  harp  strings  are  first 
scraped  with  the  greatest  possible  care.  Three  and  a 
quarter  pounds  of  potash  are  then  dissolved  in  six  pails- 


GUT-DRESSING. 


547 


full  of  water,  and  five  and  a  half  pounds  of  pearlash  are 
mixed  with  the  same  quantity  of  water,  and  the  solu- 
tion is  clarified  by  the  addition  of  a  little  alum.  The 
two  solutions  are  kept  in  stone-ware  vessels.  Stone- 
ware pans  are  then  half  filled  with  the  intestines,  and 
the  potash  liquor,  mixed  with  an  equal  quantity  of  water, 
is  poured  in  until  the  vessels  are  full.  The  intestines 
are  steeped  for  three  or  four  days  or  even  a  longer  time, 
the  solution  being  changed  twice  daily,  and  made  pro- 
gressively stronger  by  adding  each  time  some  of  the  ash- 
lye,  and  by  diminishing  the  quantity  of  water  mixed 
with  it.  Each  time  that  the  solution  is  changed,  the 
intestines  are  removed  from  the  vessels,  and  are  re- 
jDlaced  after  draining  upon  a  sloping  table,  and  after 
being  passed  through  a  thimble  in  the  manner  before 
described.  The  effect  of  the  alkaline  solution  upon  the 
intestines  is  to  bleach  and  swell  them,  and  they  must  be 
removed  from  it  upon  the  first  appearance  of  little  bub- 
bles of  gas  escaping  from  them,  or  they  will  be  softened 
and  rendered  unfit  for  use.  This  is  more  apt  to  occur  in 
summer  than  in  winter,  and  strings  of  the  best  quality 
are  made  in  the  latter  season. 

After  being  again  passed  through  the  thimble  so  as  to 
smooth  and  equalize  their  surfaces,  and  washed  in  fresh 
water,  the  intestines  are  attached  to  the  frame  in  order 
to  be  twisted.  This  frame  is  five  feet  three  inches  in 
length,  and  twenty-five  inches  in  breadth.  A  number 
of  pegs  are  fixed  in  one  of  its  sides,  and  a  double  num- 
ber of  holes  are  bored  through  the  other  side,  so  that  the 
cords  passed  through  them  are  kept  in  place  when  pegs 
are  introduced.  The  ends  of  the  intestines  are  first 
placed  together  upon  the  edge  of  the  tub  in  which  they 
have  been  soaked,  and  two  or  three  or  more  of  the  same 
diameter  and  length  are  selected,  and  fixed  to  one  of  the 


548 


GUT-DRESSING. 


double  holes  by  means  of  a  peg,  and  tlie  bodies  of  the 
intestines  are  then  drawn  out  exactly  of  the  same  length, 
and  brought  over  the  corresponding  large  pegs  on  the 
opposite  sides  of  the  frame,  the  ends  being  carried  back 
and  fixed  in  the  other  one  of  the  two  holes.  If  some  of 
the  intestines  are  not  sufficiently  long  to  stretch  across, 
they  are  sewed  to  other  pieces  as  near  as  possible  to 
the  end  of  the  cord,  so  that  the  points  may  be  near  the 
extremity  of  the  string,  and  may  not  interfere  with  the 
uniformity  of  surface  of  its  main  part.  The  intestines 
are  then  twisted  on  the  hooked  wheel  in  the  ordinary 
manner,  and  are  exposed  for  two  or  three  hours  in  the 
sulphuring  room,  after  which  they  are  forcibly  rubbed 
with  the  horse-hair  rope,  and  twisted  and  rubbed  again. 
They  are  again  exposed  to  the  vapors  of  burning  sul- 
phur, are  twisted  once  more  and  sulphured  for  a  third 
time,  after  wdiich  they  are  left  to  dry  in  a  state  of  ten- 
sion. 

The  strings  are  known  to  be  sufficiently  dry,  when 
one  of  the  strands  upon  being  removed  from  its  peg, 
shows  no  tendency  to  turn,  but  remains  in  the  straight 
position  in  which  it  is  held.  When  the  strings  have 
arrived  at  this  degree  of  dryness,  they  are  rubbed  over 
with  olive  oil,  are  cut  off  at  the  ends,  and  coiled  up  for 
sale. 

The  fourth  strings  of  violins,  which  are  wrapped  in 
wire,  or  other  strings  w^rapped  in  the  same  way,  are 
neither  sulphured  nor  oiled.  The  string  intended  to  be 
wrapped  is  cut  of  the  length  of  a  yard  and  a  quarter, 
and  one  of  its  ends  is  attached  to  the  hook  of  the  wheel, 
and  the  other  to  the  ring  of  a  whirl,  which  keeps  the 
string  stretched,  by  means  of  a  weight  at  the  end  of  a 
cord  fistened  to  it  and  passing  over  a  pulley.  The  wire 
is  then  fastened  around  the  string  close  to  the  whirl,  and, 


GUT-DRESSING. 


549 


as  the  wheel  is  made  to  revolve,  the  string  and  the  whirl 
turn  with  it.  The  workman  supports  the  string  with 
his  left  hand,  and  the  w^ire  passing  through  his  right  hand 
is  made  to  revolve  around  it  in  close  spiral  turns  until 
it  is  entirely  and  equally  covered. 

As  has  been  before  observed,  the  utmost  care  and  skill, 
on  the  part  of  the  workmen,  are  required  for  the  manu- 
facture of  harp  or  violin  strings  of  good  quality.  Too 
much  or  too  little  scraping  of  the  surfaces,  the  use  of  too 
strong  lye,  the  exposure  to  the  vapors  of  sulphur  for  too 
short  or  too  long  a  time,  or  defective  twisting,  will  any, 
or  all  of  them,  impair  the  quality  of  the  product.  Long 
experience  alone  will  enable  the  workmen  to  conduct 
the  different  operations  with  the  requisite  dexterity. 


1  »  (   t  o 


INDEX. 


A 

Abies  Canadensis  used  for  tanning,  88 
Accelerating  tanning  processes,  263 
Acid,  ellagic,  62 

gallic,  58 

melanogallic,  63 

melanotannic,  63 

osytannic,  62 

paraellagic,  63 

pyrogallic,  63 
Acids,  raising  or  swelling  by,  169 
Albumen,  a  constituent  of  skins,  45 
Aleppo  galls,  72 

Alder-bark,  tanning  power  of,  351 
Alumed  skins,  improperly  so  called,  354 
Apotheme,  65,  407 
Arecha  catechu,  68 
Artificial  tannin,  51 

B 

Bagnall's  bark-chopping  machine,  114 
Bark,  beech,  used  for  tanning,  89 
cinnamon,  tannin  in,  86 
chopping-machine  of  Bagnall,  114 
"  "  Farcot,  122 

cork-tree,  tanning  power  of,  91 
different  layers  of,  84 
Lombardy  poplar,  used  for  tanning, 
89 

mill  of  Bourgeois,  126 
"    Lespinasse,  129 
Wiltse,  131 
tanning  power  of  sassafras,  87 
Weldon's  mill  for  grinding,  119 
willow,  used  for  tanning,  92 
Barks,  84 

oak,  95 
Barking  of  trees,  104 
Barkometer,  329 
Barley-dressings,  raising  by,  180 
Bate,  or  grainer  of  dung,  350,  356 
Braconnot's  mode  of  making  gallic  acid, 
59 

Beam,  working  on  the,  202 


Beating  and  rolling  of  leather,  221 

leather,  Debergue's  machine  for, 
223 

Flotard  and  Delbut's  machine 
for,  227 

Beech-bark  used  for  tanning,  89 

Belts,  leather  for,  496 

Bell  Stephens's  process  for  estimating 

tanning  power,  109 
Bengal  catechu,  68 

Berendorf's  machine  for  pressing  hides, 
232 

Berenger  and  Sterlingue's  tanning  pro- 
cess, 263 

Beruheim's  and  Labouriau'smode  of  em- 
bossing leather,  531 

Black  oak,  100 

Bloom  on  leather,  407 

Birch  bark,  tannin  in,  86 

"         oil,  preparation  of,  376 

Bombay  catechu,  68 

Bordier's  mineral  tanning  process,  396 

Bottles  of  leather,  450 

Bookhout's  and  Cochen's  smoothing  ma- 
chine, 500 

Booth's  process  for  fair  leather,  505 

Bourgeois's  bark-mill,  126 

Bouillon-Lagrange's  mode  of  preparing 
tannin,  42 

Brown's  tan- vats,  204 

Buffalo,  or  Grecian  leather,  369 

Buffalo  hides,  151 

Bulbs  containing  tannin,  80 

Burbridge's  tanning  process,  318 

Butts,  or  red  leather,  347 

C 

Calf-skins,  150 

currying  of,  489 
English,  492 
grained,  495 
leather  for  belts,  496 
oiled,  489 
tallowed,  491 


552 


INDEX. 


Calf-sldns, 

tanning  of,  349 

waxed,  403 
Calmuck,  method  of  treating  skins,  440 
Catechu,  67 

arecha,  68 

Bombay,  68 

Bengal,  68 

cake,  67 

gambir,  68 

Pegu,  68 

tannin  from,  50 

tanning  with,  319 
Catgut,  543 
Catskill  bark-mill,  131 
Cavalin's  mineral  tanning  process,  397 
Chamois  leather,  433 
Chaplin's  tanning  process,  274 
Cinnamon-bark,  tannin  in,  85 
Clock-makers'  cord,  546 
Comparative  tanning  power  of  oak-bark, 
divi-divi,  alder,  and  catechu,  351 
Composition  of  skin,  140 
Constitution  of  the  skin,  137 
Cordage,  tanning  of,  452 
Cords  for  clock-makers,  546 

<'      hatters'  bowstrings,  545 

"      lathes,  542 

"      rackets,  545 

"      musical-instrument  strings, 
646 

"      whips,  545 
Corium,  138 

Cork-tree  bark,  tanning  power  of,  91 
Covers,  leather  for  cjdinders,  451 
Cox's  machine  for  rolling  leather,  238 

tanning  process,  275 
Crop  leather,  215 

Curandeau's  process  for  Hungary  lea- 
ther, 431 
Cutch,  67 
Cuticle,  139 
Cutis  vera,  138 
Currying  of  calf-skins,  489 

"         goat-skins,  497 

"         leather,  461 
Cylinders,  leather  covers  of,  451 

D 

Danish  tanning  process,  283 

Davy's  mode   of    estimating  tanning 

power,  108 
Deane's  water-proof  dressing,  509 
Debergue's  machine  for  beating  leather, 

223 

Degrand's  machine  for  splitting  and 

shaving  leather,  518 
Depilation  of  skins  by  barley-dressings, 

180 

cool  sweating,  176 


Depilation  of  skins  by  caustic  soda,  171 
steam,  170 

Warington's  process  for  the,  176 
Dessable's  tanning  process,  212 
Desmond's  tanning  process,  247 
Deyeux's  mode  of  preparing  tannin,  42 
Didier's  process  for  patent  leather,  456 
Dignity  of  labor,  25 

Disinfection  of  gut-dressing  workshops, 
540 

Divi-divi,  tanning  power  of,  351 
Dize's  mode  of  preparing  tannin,  42 
Domestic,  or  slaughter  hides,  150 
Domine's  mode  of  preparing  tannin,  45 
Drake's  tanning  process,  274 
Drying  of  leather,  219 
Dung  of  chickens  or  pigeons,  use  of,  350 
Dutch  or  mineral  tanning,  397 
Dye-tanning  process,  399 

E 

East's  mode  of  embossing  leather,  534 
Ellagic  acid,  62 
Embossing  of  leather,  530 

Bernheim  and  Labouriau's  process, 
531 

East's  process,  534 
English  calf-skins,  492 

Harness-leather,  349 

hides,  485 
Extract  of  oak-bark,  tanning  with,  318 
Extractive,  65 

F 

Fair  leather,  505 

Farcot's  bark-chopping  machine,  122 
Fibrine,  a  constituent  of  skins,  140 
Fibrinous  tissue,  140 
Fiedler's  mode  of  preparing  gallic  acid, 
58 

Fleshing  of  skins,  155 

Vauquelin's  machine  for  the,  257 
Flotard  and  Debut's  machine  for  beat- 
ing leather,  227 
Flowers  and  flower  tops,  tannin  in,  78 
French  bark-mill,  113 
Fruits,  tannin  in,  80 
Fulling  machines,  256,  321 

Wiltse's,  325 
Fungi,  vegetable,  containing  tannin,  70 
Furze,  tanning  with,  344 

G 

Gallic  acid,  58 

modes  of  preparing,  59 

properties  of,  60 
Galls,  70 
Gambir,  68 

Gas-works  lime,  used  for  depilation,  851 


INDEX. 


553 


Gelatine,  a  constituent  of  skins,  142 
GetlitFe's  tanning  process,  248 
Girauclon's  machine  for  splitting  and 

sliaviug  leather,  519 
Glazed  leather,  453 
Grained  calf-skins,  495 

leather,  475 
Grainer,  or  bate  of  dung,  350,  356 
Grape-skins,  tanning  with,  839 
Goat-skins,  151 

currying  of,  497 

tanning  of,  361 
Goldbeater' s-skin,  540 
Gray  oak,  102 
Gut-dressing,  536 

H 

Halvorson's  process  for  making  hides 

hard  and  transparent,  458 
Hannoye's  tanning  process,  279 
Harness  leather,  English,  345 
Hatters'  cords  for  bowstrings,  545 
Hematine,  a  variety  of  tannin,  49 
Hemlock  spruce,  used  for  tanning,  88 

tanning,  320 
Herapath  &  Cox's  tanning  process,  213 
Hershey's  machine  for  softening  hides, 
325 

Hibbard's  tanning  process,  307 
Hides,  Buffalo,  151 

definition  of,  146 

domestic,  150 

English,  485 

horse,  151 

Spanish,  or  South  American,  150 
mills,  321 

mode  of  salting,  152 

"      making  hard  and  transpa- 
rent, 458 
Horse-hides,  151 

Hungary,  leather  made  of,  429 

tanning  of,  366 
Housings  and  mats,  413 
Human  skins,  tanning  of,  368 
Hungary  leather,  415 

Curandeau's  process  for,  431 

of  cow  and  calf  skins,  428 

of  horse-hides,  429 

made  like  blackened  leather,  430 
Hydrometers,  329 

I 

Imitation  kid,  412 
Morocco,  363 
Improved  processes  for  making  leather, 
243 

Impure  tannin,  47 

Indian  mode  of  treating  skins,  441 

Intestines  of  cattle,  preparation  of,  536 

36 


J 

Jennings's  mode  of  making  leather  wa- 
terproof, 512 
Jucten,  or  Russia  leather,  372 
Juices,  tanning,  66 

K 

Kartsolf's  account  of  Russia  leather, 
379 

Keasley's  tanning  process,  291 
Kermes  oak,  97 

Kent's  mode  of  preparing  gallic  acid, 
59 

Kid  leather,  409 

imitation,  412 
Kinds  of  skins  suitable  for  tanning,  146 
Kino,  69 

Kips,  definition  of,  146 
Knowlis's  tanning  process,  275 

L 

Labor,  dignity  of,  25 
Lake-water,  160 
Lathe-cords,  542 

Laubert's  mode  of  preparing  tannin,  44 
Leather,  beating  and  rolling  of,  221 

bottles,  450 

composition  of,  ]  43 

covers  for  cylinders,  451 

crop,  215 

currying  of,  461 

different  names  of,  152 

drying  of,  219 

embossing  of,  513 

English  harness,  345 

fair,  505 

glazed,  or  varnished,  453 
grained,  475 

its  texture  and  quality,  404 
kid,  409 
losh,  438 

made  water-proof,  507 
of  Hungary,  415 
Russia,  372 
Wallachia,  885 
oiled,  433,  478 
patent,  453 
press,  260 
red,  or  Butts,  347 

"  "     currying  of,  502 

water,  478 
waxed,  484 
white,  488 
Leaves  containing  tannin,  73 
Leprieur's  tanning  process,  310 
Lespinasse's  bark-mill,  129 
Lime  used  for  raising  hides,  152 

from  gasworks  used  for  unhairing^ 
351 

Live-oak,  103  - 


554 


INDEX. 


Lombardy  poplar  bark  used  for  tanning, 
89 

M 

Machine  for  chopping  bark,  114 

"  Farcot's,  122 

for  grounding,  or  frizing,  Nisbet's, 
436 

fleshing  hides,  114 

"  "    Vauquelin's,  257 

fulling  skins,  256,  821,  325 
hammering  leather,  Debergue's, 

223 

<'  Flotard  and 

Delbut's,  227 

pommelling  and  graining  leather, 
Perkins's,  514 

pressing  hides,  Berendorf 's,  232 

rolling  leather,  Cox's,  238 

"      Wiltse's,  240 

shaving   and   cleaning  leather, 
Nossiter's,  527 

softening  hides,  Hershey's,  325 

smoothing  and  graining  leather, 
Bookhout's  and  Cochen's,  500 

splitting  and  shaving  leather,  De- 
grand's,  518 

"       "       Giraudon's,  519 
"       "       Richardson's,  525 

Marsh- water,  160 

rosemary,  tanning  with,  340 

Materials  for  tanning,  66 

Mats  and  housings,  413 

Melanogallic  acid,  63 

Melanotannic  acid,  63 

Merat-Guillot's  mode  of  preparing  tan- 
nin, 42 

Mills  for  fulling  hides,  256,  321,  325 
grinding  bark,  Bourgeois's,  126 
"     French,  113 
"  "     Lespinasse's,  129 

Wiltse's,  131 
Mineral  tanning,  395 

Bordier's  process  for,  396 
Cavalin's       "  397 
Dutch  401 
Mode  of  estimating  tanning  power,  107 
preparing  skins  with  tar  and  soot, 
342 

Mohr's  mode  of  preparing  tannin,  46 
Monier  and  Ray's  hide-mill,  321 
Morocco,  true,  361 
imitation,  363 
Myrtle,  tanning  with,  338 

N 

Nenory's  water-proof  dressings,  508 
Nets,  process  for  tanning,  452 
Newton's  mineral-tanning  process,  401 


Nisbet's  grounding  and  pumicing  ma- 
chine, 436 
Nossiter's  machine   for   shaving  and 
cleaning  leather,  527 
process  for  enamelling  leather,  457 
tanning  process,  248 
Nutgalls,  70 

0 

Oak,  black  or  quercitron,  100 
gray,  102 
Kermes,  97 
live,  103 
red,  98 

rock-chestnut,  99 
scarlet,  102 
Spanish,  98 
tanning,  245 
white,  101 
Oak-bark,  95 

tanning  with  extract  of,  318 
mills  for  grinding,  113,  126,  129, 
131 

Oaks,  American,  98 

European,  96 
Ogereau's  tanning  process,  252 
oil  of  Birch-bark,  376 
Oiled  leather,  433,  478 

calf-skins,  489 
Oxytannic  acid,  62 


Paraellagic  acid,  63 
Parchment,  446 
Patent  leather,  453 

Pelouze's  mode  of  preparing  tannin,  44 
Pegu  catechu,  68 

Perkins's  pommelling  machine,  514 
Pommelling  of  leather,  465 

and  graining  machine,  514 
Pratt,  Zadock,  the  tanner,  25 
Prattsville  tannery,  account  of,  320 
Preliminary  treatment  of  skins,  155 
Process,  Berenger  and  Sterlingue's  tan- 
ning, 263 

Burbridge's  tanning,  318 

Chaplin's  tanning,  274 

Cox's  tanning,  275 

Danish  tanning,  283 

Dessables's  tanning,  212 

Desmond's  tanning,  247 

Drake's  tanning,  274 

Getlilfe's  tanning,  248 

Hannoye's  tanning,  279 

Herapath  and  Cox's  tanning,  213 

Ilibbard's  tanning,  307 

Keasley's  tanning,  291 

Knowlis's  tanning,  275 

Leprieur's  tanning,  310 

Nossiter's  tanning,  248 


INDES. 


555 


Process,  Ogereau's  tanning,  252 

Rotcli's  tanning,  284 

Seguin's  tanning,  243 

Snyder's  tanning,  287 

Squire's  tanning,  271 

Turnbull's  tanning,  298 

Vauquelin's  tanning,  254 

Warington's  tanning,  304 
Processes,  accelerating  tanning,  263 

improved  tanning,  243 
Press  for  leather,  260 
Pressing  hides,  machine  for,  232 
Pyrogallic  acid,  63 

Q 

Quercitron,  101 
Quercus  alba,  101 

ambigua,  102 

coccifera,  97 

coccinea,  102 

falcata,  98 

primus  monticola,  99 

robur,  96 

rubra,  98 

tinctoria,  100 

virens,  103 

K 

Rain-water,  159 

Raising,  or  swelling  skins,  162 
series  of  vats,  162 
by  acids,  169 
lime,  162 

barley  dressings,  180 
sour  tan-liquor,  191 
Red  oak,  98 
Rete  mucosum,  139 
Red  leather,  or  butts,  347 
currying  of,  502 
skins,  382 
Rhatany,  composition  of,  83 
Richardson's  machine  for  splitting  and 

shaving  leather,  525 
Paver- -water,  159 
Roan,  365 

Rock-chestnut  oak,  99 
Rolling  leather.  Cox's  machine  for,  238 
"       Bookhout's   and  Cochen's 
machine  for,  500 

table,  Wiltse's,  240 
Roots  suitable  for  tanning,  82 
Rotch's  tanning  process,  284 
Russia  leather,  372 

KartsoflF's  account  of,  379 
Russet  leather,  488 

S 

Saps  containing  tannin,  66 
Sails,  tanning  of,  452 
Salting  hides,  mode  of,  152 


Sassafras  bark,  87 
Scarlet  oak,  102 

Scheele's  mode  of  preparing  gallic  acid, 
58 

Seal- skins,  152 
Seeds  containing  tannin,  SO 
Seguin's  improved  tanning  process,  243 
Serturner's  mode  of  preparing  tannin, 
43 

Shagreen,  443 
Shaving  of  leather,  464 
Sheep-skins,  151 

tanning  of,  361 
Skins,  structure  and  constitution  of,  137 

as  prepared  by  the  Calmucks,  440 
"  "  Indians,  442 

classification  of,  147 

improperly  called  alumod,  354 

of  asses  and  mules,  152 

beavers  and  bucks,  152 

calves,  150 

dogs,  151 

hogs,  151 

porpoises,  152 

sheep,  151 

fleshing  of,  155 

goldbeater's,  540 

preliminary  treatment  of,  154 

red,  382 

smoking  of,  381 

suitable  for  tanning,  146 

tallowed,  475 

washing  and  working  of,  154 
Skiver,  364 
Sleeked  leather,  471 
Smith  and  Thomas's  water-proof  dress- 
ings, 507 
Smoked  skins,  381 
Snow-water,  159 
Snyder's  tanning  process,  287 
Soaking  and  washing  of  skins,  154 

water,  influence  of  on  leather,  158 
Soda,  caustic,  used  for  depilation,  171 
Soot  and  tar,  preparing  skins  by  means 
of,  342 

Sour  tan-liquor,  raising  by,  191 
Spanish  oak,  98 

or  South  American  hides,  150 
Spilsbury's  tanning  process,  272 
Spring  and  fountain  water,  159 
Squire's  tanning  process,  271 
Statice,  84, 

tanning  with,  340 
Steam,  depilation  by,  170 
Stretched  leather,  470 
Stretching  of  leather,  467 
Strings,  musical-instrument,  546 
Structui-e  of  skins,  137 
Sumach,  tannin  from,  50 

used  in  tanning,  92 


556 


INDEX. 


Sulplmrets  of  calcium  and  sodium  for 

unh  airing,  171 
Sweating  process,  cool,  176 
Swelling,  or  raising  hides,  62 

by  lime,  162 
acids,  169 

barley-dressings,  180 
sour  tan-liquor,  191 

T 

Table  of  quantity  of  tannin  in  different 
substances.  111 

Tan  and  tanning,  89 

or  powdered  oak-bark,  113 
liquor  for  raising,  bow  prepared, 
200 

raising  by,  191 
mill,  French,  113 
Weldon's,  119 
Tannin,  artificial,  5 

coloring  salts  of  iron,  blue,  51 

"  "  green,  51 

different  modes  of  preparing,  41, 

42,  43,  44,  45,  46 
from  catechu,  50 

"   sumach,  kino,  &c.,  50 
impure,  47 
in  barks,  84 

flowers,  78 

fruits,  80 

roots,  82 

seeds  and  bulbs,  80 
tea,  76 

tree-leaves,  73 
woods,  82 
pure,  55 

table  of  the  quantity  of  in  differ- 
ent substances.  111 
varieties  of,  49 
Tanning  by  mechanical  pressure,  272 
in  a  vacuum,  275 
juices,  60 
materials,  66 
mineral,  395 

"    Bordier's  process  for,  396 

"    Cavalin's,  397 

"    Newton's,  401 
of  buck,  wolf,  and  other  skins,  368 

buffalo  or  Grecian  leather,  369 

calf-skins,  349 

horse-hides,  366 

human  skins,  368 

nets,  sails,  and  cordage,  452 

sheep-skins,  361 
power,  mode  of  estimating,  107 

of  oak-bark,  divi-divi,  alder,  and 
catechu,  351 

Davy's  mode  of  estimating,  108 

Bell  Stephens's         "  109 


Tanning,  Warington's  mode  of  estimat- 
ing, 109 
process,  204 
Danish,  283 
of  Burbridge,  318 
Chaplin,  274 
Cox,  275 
Desmond,  247 
Dessables,  212 
Drake,  274 
Getliffe,  248 
Hannoye,  279 
Herapath  and  Cox,  213 
Hibbard,  307 
Keasley,  291 
Kuowlis,  275 
Leprieur,  310 
Nossiter,  248 
Ogereau,  252 
Rotch,  284 
Seguin,  243 
Snyder,  287 
Spilsbury,  272 
Squire,  271 
Turnbull,  298 
Vauquelin,  254 
Warington,  304 
what  skins  are  suitable  for,  146 
with  extract  of  oak-bark  or  cate- 
chu, 318 
furze,  344 
grape-skins,  339 
hemlock,  320 
myrtle,  338 
statice,  340 
Tallowed  skins,  475 
calf-skins,  491 
Tan  vats  and  pits,  204 

Brown's,  204 
Tar  and  soot,  preparation  of  skins  by, 

342  , 
Tartar's  method  of  treating  skins,  440 
Tawing,  409 

Tea-leaves,  tannin  in,  76 
Terra  Japonica,  67 
Texture  and  quality  of  leather,  404 
Tromsdorff's  mode  of  preparing  tannin, 
43 

True  morocco,  361 

Turnbull's  tanning  process,  298 

U 

Unhairing  by  caustic  soda,  171 
by  steam,  170 

sulphurets  of  calcium  and  sodium, 
171 

the  cool-sweating  process,  176 
Warington's  method,  176 
lire's  mode  of  preparing  gallic  acid,  59 


INDEX. 


557 


V 

Vacuum,  tanning  in  a,  275 
Varieties  of  tannin,  49 
Varnished  leather,  453 
Vats  for  tanning,  204 

Brown's,  204 

of  a  raising  series,  1G3 
Vattiug,  method  of,  207 
Vauquelin's  fleshing  machine,  257 

tanning  process,  254 
Vegetable  fungi,  tannin  in,  70 

saps,  tannin  in,  06 

W 

Wallachia  leather,  385 
Warington's  process  for  estimating  tan- 
ning power,  109 

unhairing,  176 

tanning,  304 
V/ash-ieather,  433 
Washing  and  soaking  skins,  154 
Water,  influence  of  on  the  quality  of 
leather,  158 

leather,  478 

proof-dressings,  507 


Water-proof  dressings,  cheap  process, 
511 

Deane's  process,  509 

Jennings's,  512 

Nenory's  process,  508 
Waxed-leather,  484 

calf-skins,  493 
Weldon's  mill  for  grinding  bark,  119 

improved  mill,  121 
Well-water,  160 

Wetherill's  mode  of   preparing  gallic 
acid,  59 

Whip-cord,  manufacture  of,  546 
White  leather,  488 
oak,  101 

porpoise-skins,  152 
Willow,  bark  used  in  tanning,  92 
Wiltse's  bark-mill,  131 

rolling-table,  240 

fulling-mill,  325 
Working  skins  on  the  beam,  202 
Workshop  for  gut-dressing,  disinfection 
of,  540 


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THE  BOOKBINDER'S  MANUAL. 

THE  PYROTECHNIST'S  COMPANION.    By  G.  W.  Mortimer.    75  cts. 
WALKER'S  ELECTROTYPE  MANIPULATION.    75  cts. 


THE  AMERICAN  MILLER  AND  MILLWRIGHT'S  ASSISTANT: 

By  William  Carter  Hughes,  Editor  of  "  The  American 

Miller,"  (newspaper),  Buffalo,  N.  Y.    Illustrated  by  Drawings  of  the  most  approved 

Machinery.    In  One  Volume,  12mo  $1 

The  author  offers  it  as  a  substantial  reference,  Instead  of  speculative  theories,  which  belong  only  to  those 
not  immediately  attached  to  the  business.   Special  notice  is  also  given  of  most  of  the  essential  improvements 
which  have  of  late  been  introduced  for  the  benefit  of  the  Miller. — Savannah  Republican. 
The  whole  business  of  making  flour  is  most  thoroughly  treated  by  him. — Bulletin, 
A  very  comprehensive  view  of  the  Millwright's  business. — Southern  Literary  Messenger. 


THE  TURNER'S  COMPANION: 

Containing  Instructions  in  Concentric,  Elliptic,  and  Eccentric 

Turning.  Also,  various  Plates  of  Chucks,  Tools,  and  Instruments,  and  Directions 
for  using  the  Eccentric  Cutter,  Drill,  Vertical  Cutter,  and  Circular  Rest ;  with 
Patterns  and  Instructions  for  working  them.  Illustrated  by  numerous  Engrav- 
ings.   In  One  Volume,  12mo  75  cts. 

The  object  of  the  Turner's  Companion  is  to  explain  in  a  clear,  concise,  and  intelligible  manner,  the  rudi 
ments  of  this  beautiful  art. — Savannah  Republican. 

There  is  no  description  of  turning  or  lathe-work  that  this  elegant  little  treatise  does  not  describe  and 
illustrate.—  Western  Lit.  Messenger. 


THE  PAPER-HANGER'S  COMPANION: 

In  which  the  Practical  Operations  of  the  Trade  are  system- 
atically laid  down;  with  copious  Directions  Preparatory  to  Papering  ;  Preventiontj 
against  the  effect  of  Damp  in  Walls  ;  the  various  Cements  and  Pastes  adapted  to 
the  several  purposes  of  the  Trade ;  Observations  and  Directions  for  the  Panelling 
and  Ornamenting  of  Rooms,  &c.,  &c.  By  James  Arrowsmith.  In  One  Volum-f^ 
12mo  75  cts. 


4 


PUBLICATIONS  OF  HENRY  CAREY  BAIRD. 


THE  PAINTEH,  GILDEK,  AND  VAENISEER'S  COMPANION: 
Containing  Rules  and  Regulations  for  every  thing  relating  to 

the  arts  of  Painting,  Gilding,  Varnishing,  and  Glass  Staining ;  numerous  useful 
and  valuable  Receipts  ;  Tests  for  the  detection  of  adulterations  in  Oils,  Colours, 
&c.,  and  a  Statement  of  the  Diseases  and  Accidents  to  which  Painters,  Gilders, 
and  Varnishers  are  particularly  liable  ;  with  the  simplest  methods  of  Prevention 
and  Remedy.     Third  Edition.     In  One  Volume,  12mo,  cloth  75  cts. 

Rejecting  all  that  appeared  foreign  to  the  subject,  the  compiler  has  omitted  nothing  of  real  practical 
worth. — Hunt^s  Merchants'  ilagazine. 

An  excellent  practical  work,  and  one  which  the  practical  man  cannot  afford  to  be  without. — Farmer  and 
Mechanic. 

It  contains  every  thing  that  is  of  interest  to  persons  engaged  in  this  trade. — Bulletin. 
This  book  will  prove  valuable  to  all  whose  business  is  in  any  way  connected  with  painting. — ScoWs 
Weekly. 

Cannot  fail  to  be  useful. — JSF.  Y.  Commercial. 


THE  DYER  AND  COLOUR-MAKER'S  COMPANION: 

Containing  upwards  of  two  hundred  Receipts  for  making 

Colours,  on  the  most  approved  principles,  for  all  the  various  styles  and  fabrics  now 
in  existence  ;  with  the  Scouring  Process,  and  plain  Directions  for  Preparing, 
Washing-off,  and  Finishing  the  Goods.  Second  Edition.  In  One  Volume,  12mo, 
cloth  75  cts. 

This  is  another  of  that  most  excellent  class  of  practical  books,  which  the  publisher  is  giving  to  the 
public.  Indeed,  we  believe  there  is  not,  for  manufacturers,  a  more  valuable  work,  having  been  prepared 
for,  and  expressly  adapted  to  their  business. — Farmer  and  Mechanic. 

It  is  a  valuable  book. — Otsego  Republican. 

We  have  shown  it  to  some  practical  men,  who  all  pronounced  it  the  completest  thing  of  the  kind  they 
had  seen.— iV.  Y.  Nation. 


THE  BUILDER'S  POCKET  COMPANION: 

Containing  the  Elements  of  Building,  Surveying,  and  Archi- 
tecture ;  with  Practical  Rules  and  Instructions  connected  with  the  subject.  By 

A.  C.  Smeaton,  Civil  Engineer,  &c.  Second  Edition.   In  One  Volume,  12mo  $1 

Contents. — The  Builder,  Carpenter,  Joiner,  Mason,  Plasterer,  Plumber,  Painter, 

Smith,  Practical  Geometry,  Surveyor,  Cohesive  Strength  of  Bodies,  Architect. 

THE  ASSAYER'S  GUIDE; 
Or,  Practical  Directions  to  Assay ers,  Miners,  and  Smelters,  for 

the  Tests  and  Assays,  by  Heat  and  by  Wet  Processes,  of  the  Ores  of  all  the  prin- 
cipal Metals,  and  of  Gold  and  Silver  Coins  and  Alloys.  By  Oscar  M.  Lieber,  late 
Geologist  to  the  State  of  Mississippi.    12mo.    With  Illustrations  75  cts. 

A  TREATISE  ON  A  BOX  OE  INSTRUMENTS, 
And  the  Slide  Rule,  with  the  Theory  of  Trigonometry  and 

Logarithms,  including  Practical  Geometry,  Surveying,  Measuring  of  Timber,  Cask 
and  Malt  Gauging,  Heights  and  Distances.  By  Thomas  Kentish.  In  One 
Volume,  12mo    $1 


PTTBLICATIONS  OF  HENRY  CAREY  BAIRD. 


5 


THE  CABINET-MAKER  AND  UPHOLSTERER'S  COMPANION: 

Comprising  the  Rudiments  and  Principles  of  Cabinet-making 

and  Upholstery,  with  familiar  Instructions,  illustrated  by  Examples,  for  attaining 
a  proficiency  in  the  Art  of  Drawing,  as  applicable  to  Cabinet-Work  ;  the  processes 
of  Veneering,  Inlaying,  and  Buhl  Work  ;  the  art  of  Dyeing  and  Staining  Wood, 
Bone,  Tortoise-shell,  &c.  Directions  for  Lackering,  Japanning,  and  Varnishing  ; 
to  make  French  Polish  ;  to  prepare  the  best  Glues,  Cements,  and  Compositions, 
and  a  number  of  Receipts  particularly  useful  for  Workmen  generally,  with  Ex- 
planatory and  Illustrative  Engravings.  By  J.  Stokes.  In  One  Volume,  12mo, 
with  Illustrations  75  ctg_ 

A  large  amount  of  practical  iuformation,  of  great  service  to  all  concerned  in  those  branches  of  business 
— Ohio  State  Journal. 


HISTORY  OF  PROPELLERS  AND  STEAM  NAVIGATION: 

With  Biographical  Sketches  of  Early  Inventors.    By  Egbert 

Macfarlane,  C.  E.,  Editor  of  the  *'  Scientific  American."    In  One  Volume,  12mc. 

Illustrated  by  over  Eighty  Wood  Engravings  75  cts. 

The  object  of  this  "  History  of  Propellers  and  Steam  Navigation"  is  twofold.  One  is  the  arrangement 
and  description  of  many  devices  which  have  been  invented  to  propel  vessels,  in  order  to  prevent  many  in- 
genious men  from  wasting  their  time,  talents,  and  money  on  such  projects.  The  immense  amount  of  time, 
study,  and  money  thrown  away  on  such  contrivances  is  beyond  calculation.  In  this  respect,  it  is  hoped 
that  it  will  be  the  means  of  doing  some  good.— Pre/ace. 


A  TREATISE  ON  SCREW-PROPELLERS  AND  THEIR  STEAM- 
ENGINES, 

With  Practical  Rules  and  Examples  by  which  to  Calculate 

and  Construct  the  same  for  any  description  of  Vessels.  By  J.  W.  Nystrom.  Illus- 
trated by  over  thirty  large  working  Drawings.    In  one  Volume,  octavo  $3.50 

THE  ANALYTICAL  CHEMIST'S  ASSISTANT : 

A  Manual  of  Chemical  Analysis,  both  Qualitative  and  Quan- 
titative, of  Natural  and  Artificial  Inorganic  Compounds ;  to  which  are  appended 
the  Rules  for  Detecting  Arsenic  in  a  Case  of  Poisoning.  By  Frederik  Wcehler, 
Professor  of  Chemistry  in  the  University  of  Gottingen.  Translated  from  the  Ger- 
man, with  an  Introduction,  Illustrations,  and  copious  Additions,  by  Oscar  M. 
LiEBER,  Author  of  "  The  Assayer's  Guide."    In  one  Volume,  12mo  $1.25 


THE  FRUIT,  FLOWER,  AND  KITCHEN  GARDEN. 

By  Patrick  Neill,  L.  L.  D.,  F.  R.  S.  E.,  Secretary  to  the 

Royal  Caledonian  Horticultural  Society.    Adapted  to  the  United  States,  from  the 

Fourth  Edition,  revised  and  improved  by  the  Author.    Illustrated  by  fifty  Wood 

Engravings  of  Hothouses,  &c.  &c.    In  One  Volume,  12mo  $1.25 

This  volume  supplies  a  desideratum  much  felt,  and  gives  within  a  moderate  compass  all  the  horticultural 
information  necessary  for  practical  use. — Newark  Mercury. 
A  valuable  addition  to  the  horticulturist's  \ibv&Ty .—Baltimore  Patriot. 


6 


PUBLICATIONS  OF  HENRY  CAREY  BAIRD. 


THE  ENCYCLOPEDIA  OF  CHEMISTRY,  PHACTICAL  AND 
THEORETICAL : 

Embracing  its  Application  to  the  Arts,  Metallurgy^  Mineralogy, 

Geology,  Medicine,  and  Pharmacy.  By  James  C.  Booth,  Melter  and  Refiner  in 
the  United  States  Mint,  Professor  of  Applied  Chemistry  in  the  Franklin  Institute, 
&c. ;  assisted  by  Campbell  Morfit,  Author  of  "  Chemical  Manipulations,"  &c. 
Complete  in  One  Volume,  royal  octavo,  978  pages,  with  numerous  Woodcuts  and 
other  Illustrations.    Second  Edition.    Full  bound  $5 

It  covers  the  whole  field  of  Chemistry  as  applied  to  Arts  and  Sciences.  *  *  *  As  no  library  is  complete 
without  a  common  dictionary,  it  is  also  our  opinion  that  none  can  he  without  this  Encyclopedia  of  Chemis- 
try.— ScieMtific  American. 

A  work  of  time  and  labour,  and  a  treasury  of  chemical  information.-^iVoriA  American. 

By  far  the  best  manual  of  the  kind  which  has  been  presented  to  the  American  public. — Boston  Courier. 

An  invaluable  work  for  the  dissemination  of  sound  practical  knowledge. — Ledger. 

A  treasury  of  chemical  information,  including  all  the  latest  and  most  important  discoveries. — Baltimore 
American. 

ELEMENTARY  PRINCIPLES  OF  CARPENTRY. 

By  Thomas  Tredgold.   In  One  Volume,  quarto,  with  nume- 
rous Illustrations  $2.50 

RURAL  CHEMISTRY: 

An  Elementary  Introduction  to  the  Study  of  the  Science,  in 

its  relation  to  Agriculture  and  the  Arts  of  Life.  By  Edward  Solley,  Professor 
of  Chemistry  in  the  Horticultural  Society  of  London.  From  the  Third  Improved 
London  Edition,  12mo  $1.25 


SYLLABUS  OF  A  COMPLETE  COURSE  OF  LECTURES  ON 
CHEMISTRY: 

Including  its  Application  to  the  Arts,  Agriculture,  and  Mining, 

prepared  for  the  use  of  the  Gentlemen  Cadets  at  the  Hon.  E.  1.  Co.'s  Military 
Seminary,  Addiscombe.  By  Professor  E.  Solly,  Lecturer  on  Chemistry  in  the 
Hon.  E.  1.  Co.'s  Military  Seminary.  Revised  by  the  Author  of  "  Chemical  Manipu- 
lations."   In  One  Volume,  octavo,  cloth  $1.25 

THE  BOOKBINDER'S  MANUAL. 

Complete  in  one  volume,  12mo. 

AN  ELEMENTARY  COURSE  OF  INSTRUCTION  ON  ORDNAIJCE  AND 
GUNNERY,  AND  STEAM. 

Prepared  for  the  use  of  the  Midshipmen  at  the  Naval  School. 

By  James  H.  Ward,  U.  S.  N.    In  one  Volume,  octavo  $2.50 


STEAM  FOR  THE  MILLION. 

An  Elementary  Outline  Treatise  on  the  Nature  and  Manage- 
ment of  Steam,  and  the  Principles  and  Arrangement  of  the  Engine.  Adapted  for 
Popular  Instruction,  for  Apprentices,  and  for  the  use  of  the  Navigator.  With  an 
Appendix  containing  Notes  on  Expansive  Steam,  &c.    In  One  Volume,  8vo...372  eta 


PUBLICATIONS  OF  HENRY  CAREY  BAIRD. 


7 


HOUSEHOLD  SURGEEY ;  OR,  HINTS  OJiT  EMERGENCIES. 

By  J.  F.  South,  one  of  the  Surgeons  of  St.  Thomas's  Hospi- 
tal.   In  One  Volume,  12mo.    Illustrated  by  nearly  fifty  Engravings  $1.2.''' 

TEE  COMPLETE  PRACTICAL  BREWER; 

Or,  Plain,  Concise,  and  Accurate  Instructions  in  the  Art  of 

Brewing  Beer,  Ale,  Porter,  &c.  &c.,  and  the  Process  of  Making  all  the  Small  Beers. 
By  M.  Lafayette  Byrn,  M.  D.    With  Illustrations.    12mo  $1.00 

THE  COMPLETE  PRACTICAL  DISTILLER; 

By  M.  Lafayette  Byrn,  M.  D.    With  Illustrations. 

12mo  $1.00 

THE  PYROTECHNIST'S  COMPANION; 

Or,  A  Familiar  System  of  Recreative  Fire- Works.   By  G.  W. 

Mortimer.    Illustrated  by  numerous  Engravings.   12mo  75  cts. 

ELECTROTYPE  MANIPULATION: 

Being  the  Theory  and  Plain  Instructions  in  the  Art  of  Work- 
ing in  Metals,  by  Precipitating  them  from  their  Solutions,  through  the  agency  of 
Galvanic  or  Voltaic  Electricity.  By  Charles  V.  Walker,  Hon.  Secretary  to  the 
London  Electrical  Society,  &c.  Illustrated  by  Woodcuts.  A  new  Edition,  from 
the  Twenty-fifth  London  Edition.    12mo  75  cts. 

HOUSEHOLD  MEDICINE. 

By  D.  Francis  Condie,  M.  D.  In  One  Volume,  12mo.  Uni- 
form with,  and  a  companion  to,  the  above.    (In  immediate  preparation.) 

ELWOOD'S  GRAIN  TABLES: 

Showing  the  value  of  Bushels  and  Pounds  of  different  kinds 

of  Grain,  calculated  in  Federal  Money,  so  arranged  as  to  exhibit  upon  a  single 

page  the  value  at  a  given  price  from  ten  cents  to  two  dollars  per  bushel,  of  any 

quantity  from  one  pound  to  ten  thousand  bushels.    By  J.  L.  Elwood.   A  new  Edition. 

In  One  Volume,  12mo  $1 

To  Millers  and  Produce  Dealers  this  work  is  pronounced  by  all  who  have  it  in  nse,  to  be  superior  in  ar- 
rangement to  any  work  of  the  kind  published — and  unerring  accuracy  in  every  calculation  may  he  relied 
upon  in  every  instance. 

£p=  A  reward  of  Twenty-five  Dollars  is  offered  for  an  error  of  one  cent  found  in  the  work. 


PERFUMERY;  ITS  MANUFACTURE  AND  USE: 

With  Instructions  in  every  branch  of  the  Art,  and  Receipts 

for  all  the  Fashionable  Preparations ;  the  whole  forming  a  valuable  aid  to  the 
Perfumer,  Druggist,  and  Soap  Manufacturer.  Illustrated  by  numerous  Woodcuts, 
From  the  French  of  Celnart,  and  other  late  authorities.  With  Additions  and  Im- 
provements, by  Campbell  Morfit,  one  of  the  Editors  of  the  "  Encyclopedia  of 
Chemistry."    In  One  Volume,  12mo,  cloth.  A  new  Edition  (in  press.) 


4k  . 

8  PUBLICATIONS  OF  HENRY  CAREY  BAIRD. 


PHOTOGENIC  MANIPULATION: 

Containing  the  Theory  and  Plain  Instructions  in  the  Art  of 

Photography,  or  the  Production  of  Pictures  through  the  Agency  of  Light ;  in- 
cluding Calotype,  Chrysotype,  Cyanotype,  Chromatype,  Energiatype,  Anthotype, 
Amphitype,  Daguerreotype,  Thermography,  Electrical  and  Galvanic  Impressions. 
By  George  Thomas  Fisher,  Jr.,  Assistant  in  the  Laboratory  of  the  London  In- 
stitution.   Illustrated  by  Wood-cuts.    In  One  Volume,  24mo,  cloth  62  cts. 


MATHEMATICS  FOR  PRACTICAL  MEN: 

Being  a  Common-Place  Book  of  Principles,  Theorems,  Kules, 

and  Tables,  in  various  Departments  of  Pure  and  Mixed  Mathematics,  with  their 

Applications,  especially  to  the  pursuits  of  Surveyors,  Architects,  Mechanics,  and 

Civil  Engineers.    With  numerous  Engravings.    By  Olinthus  Gregory,  L.  L.  D., 

F.  R.  A.  S  $1.50 

Only  let  men  awake,  and  fix  their  eye,  one  while  on  the  nature  of  things,  another  while  on  the  application 
of  them  to  the  use  and  service  of  mankind. — Lord  Bacon. 


SHEEP  HUSBANDRY  IN  THE  SOUTH: 

Comprising  a  Treatise  on  the  Acclimation  of  Sheep  in  the 

Southern  States,  and  an  Account  of  the  different  Breeds.  Also,  a  Complete  Ma- 
nual of  Breeding,  Summer  and  Winter  Management,  and  of  the  Treatment  of 
Diseases.  With  Portraits  and  other  Illustratious.  By  Henry  S.  Randall.  In 
One  Volume,  octavo  $1.25 


MISS  LESLIE'S  COMPLETE  COOKERY. 

Directions  for  Cookery,  in  its  Various  Branches.   By  Miss 

Leslie.     Forty-fifth  Edition.     Thoroughly  Revised,  with  the  Addition  of  New 

Receipts.    In  One  Volume,  12mo,  half  bound,  or  in  sheep  $1 

In  preparing  a  new  and  carefully  revised  edition  of  this  my  first  work  on  cookery,  I  have  introduced 
improvements,  corrected  errors,  and  added  new  receipts,  that  I  trust  will  on  trial  be  found  satisfactory.  The 
fiuccess  of  the  book  (proved  by  its  immense  and  increasing  circulation)  affords  conclusive  evidence  that  it 
has  obtained  the  approbation  of  a  large  number  of  my  countrywomen ;  many  of  whom  have  informed  me 
that  it  has  made  practical  housewives  of  young  ladies  who  have  entered  into  married  life  with  no  other  ac- 
quirements than  a  few  showy  accompHshments.  Gentlemen,  also,  have  told  me  of  great  improvements  in 
the  family  table,  after  presenting  their  wives  with  this  manual  of  domestic  cookery,  and  that,  after  a  morn- 
ing devoted  to  the  fatigues  of  business,  they  no  longer  find  themselves  subjected  to  the  annoyance  of  an 
ill-dressed  dinner. — Preface. 


MISS  LESLIE'S  TWO  HUNDRED  RECEIPTS  IN  FRENCH  COOKERY. 

A  new  Edition,  in  cloth  25  cts. 


TWO  HUNDRED  DESIGNS  FOR  COTTAGES  AND  VILLAS,  &c.  &c., 

Original  and  Selected.    By  Thomas  U.  Walter,  Architect  of 

Girard  College,  and  John  Jay  Smith,  Librarian  of  the  Philadelphia  Library.  In 
Four  Parts,  quarto  $10 


PUBLICATIONS  OF  HENRY  CAREY  BAIRD. 


9 


STANDARD  ILLUSTRATED  POETRY. 


THE  TALES  AND  POEMS  OF  LORD  BYRON: 

Illustrated  by  Henry  Warren.   In  One  Volume,  royal  8vo, 

with  10  Plates,  scarlet  cloth,  gilt  edges  $5 

Morocco  extra  $7 

It  is  illustrated  by  several  elegant  engravings,  from  original  designs  by  Warren,  and  is  a  most  splendid 
work  for  the  parlour  or  study. — Boston  Evening  Gazette. 


CHILDE  HAROLD;  A  ROMAUNT  BY  LORD  BYRON: 

Illustrated  by  12  Splendid  Plates,  by  Warren  and  others.  In 

One  Volume,  royal  8vo,  cloth  extra,  gilt  edges  $5 

Morocco  extra  $7 

Printed  in  elegant  style,  with  splendid  pictures,  far  superior  to  any  thing  of  the  sort  usually  found  in 
books  of  this  kind. — N.  Y.  Courier. 


SPECIMENS  OF  THE  BRITISH  POETS. 

From  the  time  of  Chaucer  to  the  end  of  the  Eighteenth  Cen- 
tury.   By  Thomas  Campbell.    In  One  Volume,  royal  8vo.    (In  press.) 


THE  FEMALE  POETS  OF  AMERICA. 

By  RuFUS  W.  Griswold.    A  new  Edition.   In  One  Volume, 

royal  8vo.    Cloth,  gilt  $2.50 

Cloth  extra,  gilt  edges  $3 

Morocco  super  extra  $4.50 

The  best  production  which  has  yet  come  from  the  pen  of  Dr.  Griswold,  and  the  most  valuable  contribu- 
tion which  he  has  ever  made  to  the  literary  celebrity  of  the  country.— iV.  Y.  Tribune. 


THE  LADY  OF  THE  LAKE : 

By  Sir  Walter  Scott.   Illustrated  with  10  Plates,  by  Cor- 

BOULD  and  Meadows.    In  One  Volume,  royal  Bvo.    Bound  in  cloth  extra,  gilt 

edges  $5 

Turkey  morocco  super  extra  $7 

This  is  one  of  the  most  truly  beautiful  books  which  has  ever  issued  from  the  American  press. 


LALLA  ROOKH;  A  ROMANCE  BY  THOMAS  MOORE: 

Illustrated  by  13  Plates,  from  Designs  by  Corbould,  Meadows, 

and  Stephanoff.   In  One  Volume,  royal  Bvo.   Bound  in  cloth  extra,  gilt  edges... $5 

Turkey  morocco  super  extra  $7 

This  is  published  in  a  style  uniform  with  the    Lady  of  the  Lake." 


10 


PUBLICATIONS  OF  HENRY  CAREY  BAIRD. 


THE  POETICAL  WORKS  OF  THOMAS  GRAY: 

With  Illustrations  by  C.  W.  Kadcliffe.  Edited  with  a  Me- 
moir, by  Henry  Reed,  Professor  of  English  Literature  in  the  University  of  Penn- 
sylvania.   In  One  Volume,  8vo.    Bound  in  cloth  extra,  gilt  edges  $3.50 

Turkey  morocco  super  extra  ..$5.50 

It  is  many  a  day  since  we  have  seen  issued  from  the  press  of  our  country  a  volume  so  complete  and  truly 
ele2;ant  in  every  respect.  The  typography  is  faultless,  the  illustrations  superior,  and  the  binding  superb. — 
Troy  Whig. 

We  have  not  seen  a  specimen  of  typographical  luxury  from  the  American  press  which  can  surpass  this 
volume  in  choice  elegance. — Boston  Courier. 

It  is  eminently  calculated  to  consecrate  among  American  readers  (if  they  have  not  been  consecrated 
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B 


14 


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